Thanks for the feedback, Phil!

Not sure why the exercise (Operations on Lists, 5.4) is grading it wrong.

Hello, does anyone have errors when checking the solution for the lesson exercises in the interactive course framework at Wolfram U?

Yes. Several class participants have commented here. A fair number of correct answers get scored as incorrect, and a tiny number of incorrect answers get scored as correct. From what you described, you've clearly spent a lot of time going through those exercises.

My guess is that nobody on staff has run though all of the EIWL (third edition) exercises in a while. I'm guessing that none of the staffers associated with this course ran (walked? slogged?) through the exercises and reported problems they noticed. If you listen closely, Cassidy was emphasizing passing the quizzes and getting that certification. I think that's a good strategy.

There may be a structural problem with the EIWL exercise framework. I believe the computational resources for the EIWL interactive course run on the individual user's Wolfram Cloud account. The amount of computation resources for a free Wolfram Cloud account are limited. The entire exercise/grading engine chews up fair amount of resources -- especially on the Entity and GeoGraphics problems. And you can easily run through many questions in a session when you change between exercises chapters in the framework. It's possible the "something went wrong with grading" problems are happening because your personal account has run out of computrons. Here's the kicker: if there is a potential resource problem when actively using the EIWL framework, then Wolfram Research staffers -- with far larger resource quotas on their accounts -- probably would never hit those computational quotas. They would have a real problem reproducing any issues you might encounter.

It would be nice if @Wolfram-U could do some forensics on your Wolfram Cloud account and see if you bumped up against its resource limits in the past 1-2 weeks. If you really want to pursue your issues, this is the most likely way you have to get a resolution. E-mail wolfram-u@wolfram.com . If you'd get any answers, please post a message to this community forum. Thanks!

here I can check the solutions without error, but this way the tracking of the exercises doesn´t count at Wolfram U course for following my progress...

My personal advice is to not bother with the cert you get by completing the EIWL exercises. Work around the road-blocks and do as many of them as possible. If you do 90%+ of them, you have done the work. I think you will do just fine on the Wolfram Language Level 1 certification test. If you check over the Calculus interactive course, I think you'd do just fine on the Mathematica Level 1 cert also.

I think the EIWL interactive course exercises are outstanding. They require the kind of "fill in the blanks" thinking that the learning experts have identified as the best way to learn new material. IMHO, they are far better than any quizzes that Wolfram Research has for their other courses. The real goal is to be writing code, and you can start doing that with the EIWL exercises. At the same time, the grading engine appears to be a bit of an abandoned child in the Wolfram Research education portfolio. :(

Good work on what you've done in the exercises. I was going through the framework about 9 months ago (on my own). I got about 95% of the way through and gave up. I saw most of the failures you saw; I don't remember if I got the "something wrong with grading" error. I got the strong sense it was a Wolfram Cloud computational quota problem, but that could be completely wrong.

CC @Jamie Peterson (of Wolfram U). I really love/hate this material. It sounds like Héctor does, too.

Here is the code that I was using to parse some strings and then create a dataset from them. I guess the problem is when Mapping some of the expressions the result is a list and then this is included in a larger list. Really want to get the result without the List property, so to remove in as I have to now. The other problem is that when using RegularExpression is that the matches are returned as String and I will have to convert that later to Integer for processing.

In[553]:= lineSplit // InputForm

Out[553]//InputForm=
{{"Game 1", " 3 blue, 4 red", " 1 red, 2 green, 6 blue", " 2 green"}, 
 {"Game 2", " 1 blue, 2 green", " 3 green, 4 blue, 1 red", " 1 green, 1 blue"}, 
 {"Game 3", " 8 green, 6 blue, 20 red", " 5 blue, 4 red, 13 green", " 5 green, 1 red"}, 
 {"Game 4", " 1 green, 3 red, 6 blue", " 3 green, 6 red", " 3 green, 15 blue, 14 red"}, 
 {"Game 5", " 6 red, 1 blue, 3 green", " 2 blue, 1 red, 2 green"}}

In[549]:= fxx[arg1_] := Module[{game, sets},
  game = StringCases[RegularExpression["(\\d+)"] -> "$1"][First[arg1]][[1]];
  sets = StringCases[RegularExpression["(\\d+) (\\w+)"] -> "$2" -> "$1"][
    Rest[arg1]];
  <|Flatten[{"game" -> game, "blue" -> 0, "red" -> 0, "green" -> 0, #}]|> & /@
    sets
  ]

In[550]:= fxx /@ lineSplit (* this results in the List-of-Lists *)

Out[550]= {{<|"game" -> "1", "blue" -> "3", "red" -> "4", 
   "green" -> 0|>, <|"game" -> "1", "blue" -> "6", "red" -> "1", 
   "green" -> "2"|>, <|"game" -> "1", "blue" -> 0, "red" -> 0, 
   "green" -> "2"|>}, {<|"game" -> "2", "blue" -> "1", "red" -> 0, 
   "green" -> "2"|>, <|"game" -> "2", "blue" -> "4", "red" -> "1", 
   "green" -> "3"|>, <|"game" -> "2", "blue" -> "1", "red" -> 0, 
   "green" -> "1"|>}, {<|"game" -> "3", "blue" -> "6", "red" -> "20", 
   "green" -> "8"|>, <|"game" -> "3", "blue" -> "5", "red" -> "4", 
   "green" -> "13"|>, <|"game" -> "3", "blue" -> 0, "red" -> "1", 
   "green" -> "5"|>}, {<|"game" -> "4", "blue" -> "6", "red" -> "3", 
   "green" -> "1"|>, <|"game" -> "4", "blue" -> 0, "red" -> "6", 
   "green" -> "3"|>, <|"game" -> "4", "blue" -> "15", "red" -> "14", 
   "green" -> "3"|>}, {<|"game" -> "5", "blue" -> "1", "red" -> "6", 
   "green" -> "3"|>, <|"game" -> "5", "blue" -> "2", "red" -> "1", 
   "green" -> "2"|>}}

I will keep playing around with it and learn how to get the data structures that I need. That what I am trying to do now is learn how to perform some of the transformations that I am used to from using R

You're creating a Dataset with a list of lists of associations. What does it mean to create a Dataset with a list of list of associations? I don't know; that is kind of a funky structure. Creating a Dataset out of a list of list of associations doesn't magically remove (i.e., Flatten) that secondary structure. The entries in your Dataset are Associations. That makes no sense -- it doesn't make any sense to me. The Wolfram Language is rather promiscuous; it will let you do all sorts of things that might make no sense programatically.

That promiscuity extends to displaying dubious expressions: it tries the best it can. It looks like a simple Dataset, but using FullForm will show the whole structure:

listOfLists // Dataset // FullForm

A sane Dataset is created if you Flatten your list-of-lists input first:

listOfLists // Flatten // Dataset // FullForm

Run those 2 expressions and note that the output is dramatically different.

Anyone know what is causing the problem?

The fundamental problem is that you haven't ever specified what you're trying to do. It looks like you're trying to create a Dataset that has a two-level hierarchy with a list of games. Defining that as a list-of-list of associations appears to not work. Instead, you want to create a single list of associations, and have each of those associations have some structure within them.

I asked my friendly neighborhood AI how one would go about doing that:

how do you create a nested database in the Wolfram Language

It provided two examples. Here's the first:

data = {
  <|"game" -> "Game 1", 
    "players" -> {
      <|"name" -> "Alice", "score" -> 5|>, 
      <|"name" -> "Bob", "score" -> 7|>
    }|>, 
  <|"game" -> "Game 2", 
    "players" -> {
      <|"name" -> "Alice", "score" -> 8|>, 
      <|"name" -> "Charlie", "score" -> 6|>
    }|>
};

dataset = Dataset[data]

I ran that. If you create that Dataset, you'll see the 2-level structure in place. Row and column selection should work just fine on that Dataset. The structure is created in each association, but only one simple list of those associations is passed to create the Dataset. I strongly recommend asking questions like this to ChatGPT; it has a great breadth of knowledge in the Wolfram Language. Just be a skeptic and double-check everything it gives you. Don't be thrown if ChatGPT gives you a slightly different response to the response I showed above. The reply that Chat gives to any question is influenced by the context of the earlier conversation. A poet might call that the butterfly effect of AIs: getting a different response when two questions appear to be identical.

@Jim Holtman, I think these are great explorations. EIWL gives a broad introduction to the language, but it doesn't go into great depth of any of them. You're exploring something beyond the flat Datasets that were shown in the book and course. I definitely learned something by poking around with your question. I fondly hope my response was helpful.

If you looked at the "Traveling Educator" message that I posted here -- the big path on a US map -- you'll see that I had simple text that I was importing into a Dataset. I used SemanticImportString to import that data. There was a bug in my interpretation and my output: my data source had put "Sat" before a date in the table I imported. Look at the output in the dataset: the SemanticImport left that field blank in the dataset it generated. All things equal, I wish that SemanticImportString had generated an error when it saw that unanticipated day-of-week, but it silently put a blank field in. The function didn't complain, and I missed the buggy entry in my database.

You have some blank spots in your data. Whether or not you have blank spots, you need to canonicalize your input. If you're exporting from some database, it should already be canonicalized. If your input isn't coming from a database, you have your choice of tools to massage it. If privacy is not an issue, you could even use ChatGPT to put your data into a form more palatable to input into a database -- any database.

I did one manual massage on my data. Gil had listed Minneapolis St. Paul as a "city" in his list. This is completely understandable by humans what he means -- the twin cities -- but it befuddled the Wolfram Language to put a place-marker for that non-city.

Importing data is definitely a black art. Importing your data will probably wind up being the most difficult part of your task. I suggest downloading the ".txt" file I included with that message, running the code, and scrutinizing the intermediate results. I suspect that some flavor of SemanticImport is what you need.

I do enjoy using these AI tools to help solidify understanding!

Thanks for the input. I had looked at sorting and that will work if I have all the values. I am reading in some data that has hundreds of records and many may be missing one, or more, of the fields. What is hard is determining which ones are missing. Since these are Associations I was thinking that I would initialize with a string with all the fields being Missing <|"field"->Missing, "field"->43|> and then add the fields from each record. If there are valid ones at the end of the Association, they should be the ones that are defined [in the example, "field" would be 42]. Will try that out to see if it works. It does work. I put all the fields that I know are in the data at the start of the association initialized to 0, and then follow it with the actual data. Since an association only keeps that last value defined, it works out and also "sorts" the data in the order of the fields that are input. So with a little processing I can get that data I want.

I just found a new tool for expanding your understanding of the Wolfram Language. If you ask ChatGPT:

give me a natural-language explanation of what Graphics[ Table[{Hue[RandomReal[]], Line[RandomReal[1, {2, 2}]]}, {100}]] does in the wolfram language

I'll show the response as a graphic, since ChatGPT puts in some nice formatting:

That code is from the Neat Examples section of the Wolfram Language Documentation for Line . The really nice part is the breakdown that ChatGPT gives for the code. Using Chat to generate snippets of code from natural language is pretty well-known; using Chat to provide lucid explanations of a code fragment is a new one for me. Warning: ChatGPT (and all the AIs) will give out wrong answers. Read what the AI has said, and make sure that the response is actually intelligent. As a famous politician once said, "Trust, but verify."

Rory was commenting today that assigning values to variables happens in the final third of EIWL -- a noteworthy choice. In his announcement of the Elementary Introduction to the Wolfram Language book (2015), Stephen Wolfram had some interesting things to say on this topic. He also had interesting commentary elsewhere about individuals who started with the Wolfram Language parachuting into other language. If you open that up and search for "functional programming", you'll find this:

But what happens when someone who’s learned programming in the Wolfram Language wants to do low-level programming in C++ or Java? I’ve seen this a few times, and it’s been quite charming. They seem to have no difficulty at all grasping how to do good programming in these lower-level languages, but they keep on exclaiming about all the quaint things they have to do, and all the things that don’t work. “Oh my gosh, I actually have to allocate memory myself”. “Wow, there’s a limit on the size of an integer”. And so on.

The transition from the Wolfram Language to lower-level languages seems to be easy. The other way around it’s sometimes a little more challenging. And I must say that I often find it easier to teach computational thinking to kids who know nothing about programming: they pick up the concepts very quickly, and they don’t have to unlearn the idea that everything must turn into loops and conditionals and so on.

The WL is a challenging beast to wrap your head around. Stephen is proposing that that difficulty is not really his fault. :)

No file was attached to your message.

After coming back from my running of the day for refresh, I read your respose (THANK YOU!), Jingzhou Na. Then, I read my question. Ah-ha! Now, I understand that it was, yes, rambled, but the correct English. However, again, lol... Is there any crystal-clear expression on it? "a random multiple of tenths of a second up to 10 tenths of a second"

THANK YOU again, Jingzhou Na.

Attachments:

thumb up.jpg

• 12.7
  Generate a sequence of 10 notes with random pitches up to 12 and random durations equal to a random multiple of tenths of a second up to 10 tenths of a second. -> what does "a random multiple of tenths of a second up to 10 tenths of a second" mean? I think that it is rambled. My idea is that it may mean "RandomInteger[10]/10." Thus, I tried and "Correct" Answer was marked. Then, is that the correct English expression???

Very interesting. The "expected output" in my interface is indeed the true solution to the question (satisfying the question): when n=5, it has 5 colors and so on.

The 2nd edition solution (or the "expected output" in Phil's interface) has 6 colors when n=5, which is a false solution to the question (it does not satisfy the question).

I believe Phil's solution marked as "correct" is the true solution. There is something going wrong with the "expected solution" in Phil's interface but not in mine, which is interesting.

One guess: Phil is working on a previous version of exercise notebook that has not fixed this specific issue. Then the wrong "expected output" matches the wrong solution in 2nd edition of the book.

Attachments:

ex9.7.png

Ex9.7 and Ex14.7 does not work, the solutions are wrong in the sense that the output is not the same as desired output (does not satisfy the question)

You are awfully fast, @Jingzhou Na. We weren't ignoring you; we're just trying to catch up. :) I'm only up to 9.7. I can confirm that there's something broken with that question. If I put in an answer scored as correct, I get different behavior than the "expected output". With an input value of 5 to both manipulates, the "expected output" displays 6 colors. My "correct" output displays 5 colors. That ain't right. I covered over my submitted answer:

I have thought that this daily study group community threads help Wolfram improve their publishing/published study materials. Thus, although it takes time for us to post issues while studying, it is also one thing that we, daily study group attendees, can do for Wolfram as an expression of our appreciation for teaching us and granting us the public access to their great knowledge-based materials and lectures.

Personally, to me, this community threads help me learn that I am not alone to have the issues and can also learn from others by exchanging our experiences, and academic and empirical knowledge. I appreciate Wolfram, in particular, Wolfram U Team, who hosts and administers classes to the public for free. Moreover, I am grateful to all attendees of Wolfram classes to share their knowledge, experiences, and wisdom.

I have been thinking that we appreciate the instructors in general. However, it is easy for us to forget other Wolfram staff who make the classes run well.

THANK YOU, Rory and Eryn for teaching us. I know very well how much time you invest to teach us.

THANK YOU, Cassidy, Roberto, Christine, and Wolfram System Engineers!

What Wolfram does to the public makes a big difference on learners' ends!!! My experience says that Wolfram, in particular, Wolfram Instructors, knows about it very well.

THANK YOU, all other Wolfram attendees!

It's fall now, although it's still sweltering during the daylight due to the global warming (too sweltering.. I am allergic to Sun (lol)). Have an amazing Fall, everyone! See you around...

Sincerely,

Soomi Cheong

Table[Part[{Red, Yellow, Green}, RandomInteger[2] + 1], 100]

I tried 3 out 5 of your solutions as well. Eventually I lost my interest exploring all possibilities of different syntax giving a desired solution (at least for this one, and for some questions that does not allow changing variable names >W<, also in sec 16 about nature language expressions)

If you are really struggle with the syntax like me do, the 2nd edition solution can be found and apparently some of the solutions work for 3rd edition as well (Ex 9.7 does not work, it is even a wrong solution, I believe they fixed that in 3rd edition)

https://www.wolfram.com/language/elementary-introduction/2nd-ed/answers-to-exercises.html

I believe your answer is one correct way, but the system does not have that in the solution checker. I tried ToUpperCase[StringJoin[Alphabet[]]]

I agree that the checker is often too picky, but I agree with the checker in this case. Capitalize[] capitalizes the first letter of a string; ToUpperCase[] returns a string all in upper case. The results in this example are the same, because the strings are all one letter long. If the example had used samples from WordList[] rather than Alphabet[], then Capitalize[] would have given the incorrect result.

Part of the point of these exercises is to discover new functions. The words for the exercise are usually chosen carefully. If you get stuck on a problem, one possibility is to put words from the exercise instructions into the Wolfram Language & System Documentation Center search box and see what functions pop up. Or look in the guidelines for a major area of the documentation -- like Strings & Text. I liked Rory's comment today where [I believe] he said he spends the majority of his day inside of the documentation.

I believe your answer is one correct way, but the system does not have that in the solution checker. I tried

ToUpperCase[StringJoin[Alphabet[]]]

This one join everything as a single string "ab...z" and then capitalized the single string. {"a", "b", ..., "z"} -> "ab...z" -> "AB..Z" Your syntax gives the same result, it capitalized 26 alphabets and then join them into one single string. {"a", "b", ..., "z"} -> {"A", "B", ..., "Z"} -> "AB..Z"

For plenty of exercises, I do not think there is the best (or the simplest) answer. But seems the system does >_<.

Attachments:

ABC-XYZ.png

I find this name confusing.

The Wolfram Language is a foreign language, and it's rather idiosyncratic. Some of the function names make perfect sense; some do not. The list of sensible function-names may even vary from person to person. The important thing is that we're able to find a function that we need at the time. When I need to look up a function, I search with google describing the function a bit. In this case:

wolfram documentation find which number matches a letter of the alphabet

We are fortunate that wolfram is a rather esoteric word in all languages; having that one word in searches will typically home in on the Wolfram Language. The first hit on the above search was the webpage for the FromLetterNumber function in the Wolfram Language and System Documentation Center. I also have great luck searching with ChatGPT. ChatGPT can do many marvelous things with the Wolfram Language. I have the free/limited account with ChatGPT, but one can do lots by carefully asking a few questions daily. It's kinda like a genie that gives you three wishes, but you get your wish-count renewed every single day.

Hi Rory, I have no idea how to insert images into the code. I tried copy and paste, and it doesn't work

Both Copy/Paste and Drag/Drop work just fine on my Mac. See attachment.

You can also use Import[] to import an image to the Wolfram Language App from the file system on your local machine or from a URL. Not Rory, but HTH.

Attachments:

DraggingAnImageT...nb

What is the ideology of the following name of a WL function:

FromLetterNumber

I find this name confusing.

Hi Rory, I have no idea how to insert images into the code. I tried copy and paste, and it doesn't work. Apparently, I'm not familiar enough with the very basics of how to copy and paste in Mathematica. Please help.

Bugs with names of variables fixed in the answers, while this should be flexible

7.4 Make a list of colors with hues varying from 0 to 1 in steps of 0.1:

Table[Hue[h],{h,0,1,0.1}] - only with the variable name "h" the answer is accepted as correct

Table[Hue[x],{x,0,1,0.1}] - any other variable name is incorrect

7.8 Make a list of numbers from 0 to 1 in steps of 0.1, each with a hue equal to its value:

Table[Style[n,Hue[n]],{n,0,1,0.1}] - only with the variable name "n" the answer is accepted as correct

Table[Style[h,Hue[h]],{h,0,1,0.1}] - variable names "h", "x" or "a" are not accepted

:-(

I agree. It seems like they're split into roughly 10 chapters each, so you should be able to do quiz 1 by the end of today's class.

In the BigMarker video (I do not know any other videos) of Tuesday's second lecture in the course

The other videos are the ones in the EIWL framework itself -- 48 chapters of the book.

You're right. Eryn made a mistake working the exercise. Her answer was only fractionally correct.

I will try to give a correct reference:

In the BigMarker video (I do not know any other videos) of Tuesday's second lecture in the course @15:00 Eryn was discussing the exercise with a list of fractions. She did not erase the initial 1, while the question asked to start the list with 1/2.

THANK YOU, Phil.I will keep in mind your thoughtful advice.

See you around, Phil.

Thanks, Soomi. There are plenty of superior Wolframers (is that a word?); they're just not around this course. Our course instructors are far more qualified. Cassidy is pretty darn qualified too, but she rarely shows her technical chops in courses.

I do hope that the answers (all correct ones) and solutions are available once we finish each exercises.

I understand the sentiment, but I strongly disagree. The goal is to learn, which may not mean getting the right answer. Be tenacious in seeking the expected result, but don't drown in frustration if you can't find it. Sometimes, there's some point to the exercise that may not be obvious on the first (or fifth) try. In those cases, seek to outflank the problem. Look up the official documentation describing the function. You may find the solution there. You may learn something that helps your overall Wolfram knowledge but has nothing to do with the exercise. That's all part of the game. I remember being extremely frustrated when I ran through [most of] the interactive course; I actually abandoned getting the cert.

When you have some time, I recommend checking out Conrad Wolfram's 2010 TED Talk. He's commenting on the fallacious way we teach math in school. It's not about getting the right answer; it's about knowing how to think and learn in a particular system. This course is a bit different: we're learning the [arbitrary] framework of the Wolfram Language; all of its idiosyncrasies. The goal of the exercises is to learn the language: listening/reading and then speaking/writing. Try like heck to get the exercises right, but realize that that's never the goal. And -- please -- have fun in the process. Respect the exercise framework, but have a healthy lack of respect for it, too.

It's asking you specifically to use power, so multiplication will be incorrect, as you haven't answered the question, even though the output is the same :)

The solution in the video recording is wrong. You have got 4. But 4<10.

If you're going to reference a video, please say which exact video you're discussing and provide a timestamp. It looks like you're talking about the BigMarker video of Monday's first lecture in the course @38:05. Rory was discussing the exercise with RandomInteger[]. He showed:

Plus[RandomInteger[{1,10}],RandomInteger[{1,10}]]

and ran that computation several times. One of those results was 4. I'm certain the grading engine would score his expression above as wrong. I don't think Rory was trying to solve the exercise; he was showing an expression close to what was asked in the exercise. You're right: his language may have been a bit ambiguous.

Dear Soomi,

You should use your own intelligence and predict the intended answer. Then, code the answer using WL. Do not expect too much from algorithms. Your answers were not real simplifications. Only if we have one list in one piece, then we can be happy with the simplification. I see that some versions of codes giving {1,2,3,4,5} are possible.

@Rory/@Eryn , there's a problem displaying plots when running Wolfram Cloud on an iMac (24-inch M1 2021, macOS 14.6.1, Safari 17.6): tic marks are not scaled correctly. This shows up in the EIWL course framework. For example, Exercise 3.6 looks like this on that hardware/software:

I reported this bug to Wolfram Technical Support (CASE:5170014) back at the end of August. I think I went through all the steps, but I have no sense how long it takes to fix a bug in the cloud environment. They asked me for the $CloudVersion which has the bug; it's now 1.69.0.1 (September 4, 2024).

The problem doesn't happen in the Google Chrome browser on the iMac. I will switch to Chrome. This is a FYI if other students encounter this on an iMac. If you have access to look up the bug report internally, I'd be grateful if you'd see if they're waiting for me to do something.

Thank you for the pep talk, Phil - you are the smartest and the best Wolfram learner, as I have observed. I really appreciate it. I do hope that the answers (all correct ones) and solutions are available once we finish each exercises.

Yes. The engine tries hard, but it doesn't always get it right. When the examples get more complex, the engine gets far more interesting. I'd love to have a peek under the hood.

You've gotten right answers shown as wrong by the grading-engine. The real challenge is to submit a wrong answer and have the engine judge it as right. Game on, @Soomi

Exercise 1.4 Compute 5 squared (i.e. 5x5 or 5 raised to the power 2)

->

(My solution)

5x5

5^2

->

the framework says only 5x5 is correct.

->

both of them are correct answers, right? (Hmm... too many wrong answers..)

Attachments:

Exercise-1.4.jpg

Exercise 3.9

Find a simpler form for Join[{1,2},Join[{3,4},{5}]]

-> (My solution)

Join[{1,2},{3,4},{5}]

->

My solution is correct. However, the framework says that it is not.

->

What is the answer? (not again..)

Attachments:

Exercise-3.9.jpg

Exercise 3.6 Plot a list that counts up from 1 to 100, then down to 1.

->

(My solution)

As attached,

ListPlot[Join[Range[100],Reverse[Range[100]]]]

->

However, the framework says that it is not correct.

->

Then, what is the correct answer??? And, why???

• Rory, it seems like that many exercise answers are not correct (lol). -> Should I post each of them whenever I find them?

Attachments:

Exercise-3.6.jpg

Hi! It looks like there's a resource function that does what you're looking for here.

An easy way to use a resource function is to hover over the title of the function on the webpage so you get the click-to-copy UI, then click on the copy button and paste it into your notebook.

I think a good answer would probably be the easiest (in class, I was aiming to show a more complex solution)

Plus[10, RandomInteger[{1,10}]

Exercise 2.5 Use Plus and RandomInteger to generate a random integer between 10 and 20.

-> (Your solution)

RandomInteger[{1,10}] -> generates a random number between 1 and 10

Then,

Plus[RandomInteger[{1,10}, RandomInteger[{1,10}] -> generates a random number between 2 and 20, not between 10 and 20

(My solution)

RandomInteger[{5,10}] -> generates a random number between 5 and 10

Thus,

Plus[RandomInteger[{5,10}, RandomInteger[{5,10}] -> generates a random number between 10 and 20

• What do you think?

• I tried your solution to doublecheck my idea. Then, the output is between 2 and 20, as attached.

->

The framework also says that it is not correct.

->

Then,

what is the correct answer???

Attachments:

Exercise-2.5.jpg

One other recommendation you may want to announce to the class: if you download directly the notebooks for EIWL, you can "read along". Those notebooks will play in the Wolfram Language App. They will also download and play them in the Wolfram Player.

The notebooks for this course are pretty big: 250MB.

I love the exercise grading engine for the EIWL interactive course. Submitting code fragments is so much better than multiple-choice questions. Will we be doing the exercises from there in this course?