Statement 1:binaras wrote:If S is a sequence of consecutive multiples of 3, how many multiples of 9 are there in S?
(1) There are 15 terms in S.
(2) The greatest term of S is 126.
Look at this sample of consecutive multiples of 3. 3 6 9 12 15 18 21 24 27
Every third number is a multiple of 9.
15 is divisible by 3. So 15 consecutive multiples of 3 will have 5 consecutive sets of 3 multiples of 3, and each of those 5 sets will contain one multiple of 9, for a total of 5 multiples of 9.
Sufficient.
Statement 2:
This provides no way to determine the number of numbers in the sequence. Without knowing how many numbers are in the sequence we can't determine the number of multiples of 9.
Insufficient.
The correct answer is A.
