how many integers less than 20 - brute force?

[GmatGreen]

How many positive integers less than 20 are either a multiple of 2, an odd multiple of 9, or the sum of a positive multiple of 2 and a positive multiple of 9?

A) 19
B) 18
C) 17
D) 16
E) 15

Is brute force the best way to solve?

[Patrick_GMATFix]

I'd use brute force since the number set is so small that it should take under a minute. The solution below is taken from the GMATFix App. My signature below has more info.



-Patrick