The Correct answer is C.
Explanation
The intersection of sets 
and 
is the set of integers that are in 
and also in 
. Set
consists of all positive integers that are multiples of 
, and set 
consists of all positive integers that are multiples of 
, so the intersection of 
and 
is the set of positive integers that are multiples of both 
and 
. This is the set of all positive integers that are multiples of 
. There are an infinite number of positive integers that are multiples of 
, so there are more than thirteen integers in the intersection of 
and 
.
Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
If S is the set of positive integers that are multiples of 7, and if T is the set of positive integers that are multiples of 13, how many integers are in the intersection of S and T?
(A) None
(B) One
(C) Seven
(D) Thirteen
(E) More than thirteen
