A is the average (arithmetic mean) of the first 7 positive multiples of 5 and B is the median of the first 3 positive multiples of positive integer n. If the value of A^2 – B^2 is zero, what is the value of n?	Choose the correct choice from the following answers: A) 5 B) 6 C) 10 D) 15 E) 20
If A^2 - B^2 = 0, then let's assume that A = B.   A must equal the 4th positive multiple of 4, thus A = 20, which also equals B.   B is the second positive multiple of n, thus n = 20/2= 
<gadget id="calculator">20/2</gadget>
<output>10</output>
10.   The answer is 10.
<result>C</result>
A is the average (arithmetic mean) of the first 7 positive multiples of 5 and B is the median of the first 3 positive multiples of positive integer n. If the value of A^2 – B^2 is zero, what is the value of n?