Bunuel wrote:
If positive integer P is a multiple of 22 and positive integer Q is a multiple of 55, is PQ a multiple of 70?
(1) Q is a multiple of 49
(2) P is a multiple of 4
Project DS Butler Data Sufficiency (DS3)
For DS butler Questions Click Here Question Stem Analysis:We need to determine whether PQ is a multiple of 70 = 2 * 5 * 7. We are told that P is a multiple of 22, which means PQ contains a factor of 2. We are also told that Q is a multiple of 55, which means PQ contains a factor of 5. If we can determine that PQ also contains a factor of 7, we can conclude that PQ is a multiple of 70.
Statement One Alone:\(\Rightarrow\) Q is a multiple of 49
Thus, Q contains a factor of 7, which in turn means that PQ contains a factor of 7. Since PQ contains a factor of 2, 5, and 7, PQ is a multiple of 70. Statement one alone is sufficient.
Eliminate answer choices B, C, and E.
Statement Two Alone:\(\Rightarrow\) P is a multiple of 4
While we know that P is a multiple of 4, we cannot determine whether P also contains a factor of 7. If P = 44 and Q = 55, then PQ is not a multiple of 70. On the other hand, if P = 308 and Q = 55, then PQ is a multiple of 70. Since there are more than one possible answers to the question, statement two alone is not sufficient.
Answer: A _________________