When positive integer n is divided by 3, the remainder is 1. When n is divided by 7, the remainder is 5. What is the smallest positive integer k such that k+n is a multiple of 21? Select
A) 2	B) 4	C) 6	D) 8	E) 10
n = 3p + 1 = 7q + 5   n+2 = 3p + 3 = 7q + 7   n+2 is a multiple of 3 and 7, so it is a multiple of 21.   The answer is 2.
<result>A</result>
When positive integer n is divided by 3, the remainder is 1. When n is divided by 7, the remainder is 5. What is the smallest positive integer k such that k+n is a multiple of 21?