BTGModeratorVI wrote: ↑Thu Jul 23, 2020 6:36 am
Is x > 16?
1) x/4 > 4
2) 4/x < 1/4
Answer:
A
Source: Math Revolution
Target question: Is x > 16?
Statement 1: x/4 > 4
Multiply both sides by POSITIVE 4 to get: x > 16
Perfect!!
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: 4/x < 1/4
Multiply both sides by POSITIVE 4 to get: 16/x < 1
NOTE: we must avoid the temptation to multiply both sides by x to get: 16 < x. Doing so would be incorrect since we don't know whether x is POSITIVE or NEGATIVE.
Aside: for more on this, see our free video here:
https://www.gmatprepnow.com/module/gmat ... /video/979
There are several values of x that satisfy statement the fact that 16/x < 1. Here are two:
Case a: x = 20, in which case
x > 16
Case b: x = -1, in which case
x < 16
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer = A
Cheers,
Brent
