ziyuenlau wrote:Is positive integer n a multiple of 12?
1) n is a multiple of 6
2) n is a multiple of 24
Target question: Is positive integer n a multiple of 12?
Statement 1: n is a multiple of 6
There are several values of n that satisfy statement 1. Here are two:
Case a: n = 12, in which case
n IS a multiple of 12
Case b: n = 18, in which case
n is NOT a multiple of 12
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: n is a multiple of 24
This means we can write n = 24k (where k is an integer)
Since 24 = (
12)(2), we can say that n = (
12)(2)k
Since we can write n as
12 TIMES some integer, we can be certain that
n IS a multiple of 12
Since we can answer the
target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent
