Hi All,
It looks like everyone is comfortable with the Algebra involved in this question, which is good (you'll use those skills on a number of questions on Test Day). You don't actually have to do Algebra though to solve this problem (if you recognize the pattern in the original ratio).
We're given the ratio:
W:X:Y
1:2:3
So the 3 variables COULD be...
1, 2 and 3
2, 4 and 6
3, 6 and 9
4, 8 and 12
5, 10 and 15
Etc.
Notice how the "spread" in each option is unique. For example, the ONLY time that Y and W differ by 2 is in the first option (as the variables get bigger, the "spread" gets bigger). We can use THAT knowledge to our advantage.
We're asked for the value of W + X.
Fact 1: X - W = 5
The ONLY time that X-W = 5 is in the 5th option. As X gets bigger, the difference between X and W gets bigger.
W+X = 5+10 = 15
Fact 1 is SUFFICIENT
Fact 2: 3Y - 2W = 35
This is just another relationship between 2 variables, so we KNOW there's only ONE way for 3Y-2W to = 35. It's the 5th option.
W+X = 5+10 = 15
Fact 2 is SUFFICIENT
Final Answer:
GMAT assassins aren't born, they're made,
Rich