VJesus12 wrote:If x = 1 - 2y, what is z?
(1) 5x + 10y + z = 5
(2) x = 17 + 2y
Target question: What is the value of z?
Given: x = 1 - 2y
Statement 1: 5x + 10y + z = 5
Replace
x with
1 - 2y to get: 5(
1 - 2y) + 10y + z = 5
Expand: 5 - 10y + 10y + z = 5
Simplify: 5 + z = 5
Solve:
z = 0
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: x = 17 + 2y
Replace
x with
1 - 2y to get:
1 - 2y = 17 + 2y
Solve: y = -4
We still have no idea about the
value of z
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
