BTGModeratorVI wrote: ↑Thu Aug 20, 2020 7:11 am
Is r < 10 ?
(1) r < −2
(2) r ≤ 10
Answer: A
Source: Economist GMAT
Target question: Is r < 10 ?
Statement 1: r < −2
If r is LESS THAN -2, then r is clearly NEGATIVE, which means
r must be less than 10
Statement 1 is SUFFICIENT
Alternatively, if we recognize that -2 < 10, we can combine this information with Statement 1 to get: r < 2 < 10
So, the answer to the target question is
YES r is less than 10
Statement 1 is SUFFICIENT
Statement 2: r ≤ 10
Consider these two possible cases:
Case a: r = 9, in which case the answer to the target question is
YES r is less than 10
Case b: r = 10, in which case the answer to the target question is
NO r is not less than 10
Since we can't answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
