gmat.beat.it wrote:Is |x| = y - z?
1) x + y = z
2) x < 0
My Answer is A). Please correct me if I am wrong.
(1) x + y = z
If x = 1, y = 1, then |x| = 1 and y - z = 1 - 2 = -1. Here |x| is not equal to y - z.
If x = -1, y = 1, then |x| = 1 and y - z = 1 - 0 = 1. Here |x| = y - z.
No definite answer; NOT sufficient.
(2) x < 0 does not mention about y and z; NOT sufficient.
Combining (1) and (2), x + y = z such that x < 0.
If x = -1, y = 1, then |x| = 1 and y - z = 1 - 0 = 1. Here |x| = y - z.
If x = -4, y = 0, then |x| = 4 and y - z = 0 + 4 = 4. Here |x| = y - z.
It can be seen from the above examples that |x| = y - z; SUFFICIENT.
The correct answer is
C.
