BTGModeratorVI wrote: ↑Mon Jun 22, 2020 6:15 am
What is the ratio of y to x ?
(1) x/y = 2
(2) x − y = 2
Answer:
A
Source: Economist GMAT
We can rephrase the target question as follows:
Target question: What is the value of y/x?
Statement 1: x/y = 2
In other words, x/y = 2/1
Flip both sides to get:
y/x = 1/2
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: x − y = 2
If we try to algebraically manipulate this equation, we'll find it impossible to create the fraction (ratio) y/x.
This leads me to believe that statement 2 is not sufficient.
To demonstrate this, Let's test some values of x and y that satisfy statement 2:
Case a: x = 3 and y = 1. In this case, the answer to the target question is
y/x = 1/3
Case b: x = 5 and y = 3. In this case, the answer to the target question is
y/x = 3/5
Since we can't answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
