M7MBA wrote:Is x+y > 0?
(1) x > y
(2) x + y -1 > 0
Target question: Is x+y > 0?
Statement 1: x > y
Let's TEST some values.
There are several values of x and y that satisfy statement 1. Here are two:
Case a: x = 2 and y = 1 (this satisfies the condition that x > y). In this case, x + y = 2 + 1 = 3. So, the answer to the target question is
YES, x+y IS greater than 0
Case b: x = 0 and y = -1 (this satisfies the condition that x > y). In this case, x + y = 0 + (-1) = -1. So, the answer to the target question is
NO, x+y is NOT greater than 0
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: x + y -1 > 0
First recognize that x + y > x + y - 1, we can now say: x + y > x + y - 1 > 0
Now, if we ignore the x + y - 1 part, we can see that x + y > 0
So, the answer to the target question is
YES, x+y IS greater than 0
Since we can answer the
target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent
