Hello, I have the following problem:
Tickets are being sold. There is a 1/8 probability that you get a special ticket, which is free.
How many tickets would you have to buy to get at a probability of getting 1 ticket of at least 50%
This is how I solved it in Mathematica:
Solve[0.5 == Sum[Binomial[x, i]*(1/8)^i (7/8)^(x - i), {i, 1, x}], x]
It gives me an output of x → 5.19089, which is correct, but GeoGebra was able to solve it Symbolically and got
Log[2]/(3 Log[2] - Log[7])
which is equal to 5.190…
My Question is how do I get mathematica to give me that symbolic result? When i solve it also gives me this warning: Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found; use Reduce for complete solution information.
Any help is appreciated. 