Mathematica help

Questions
1

This is my first coding class, and I am struggling to learn to code. My professor does not teach us much beside giving us a worksheet.

I am trying to do the following (#16 on the attachment)

Construct a rule to zero all odd numbers in the list {1,2,3,4,5}.

2

{1, 2, 3, 4, 5} /. x_?OddQ → 0
The help section of Mathematica is a wonderful resource to get acquainted with the rule-based programming.