Hard coding like this is just plain stupid.

I would like to mention that this technically does not work for every case...

For example:
solution("bill", "il")
returns true. This is not good practice. This is why you need to write tests for edge cases.

num = 0 num += s.count('a') num += s.count('e') num += s.count('i') num += s.count('o') num += s.count('u')
Could be shortened to
num = s.count('a') + s.count('e') + s.count('i') + s.count('o') + s.count('u')

There are better solutions like this one: https://www.codewars.com/kata/reviews/54ff37ee355cfd937000105c/groups/5516d2be89154750710009cc

or mine: https://www.codewars.com/kata/reviews/54ff37ee355cfd937000105c/groups/5516d2be89154750710009cc