Task: Question Answering
Input (English): Problem: 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 ?
Options: a. 5, b. 6, c. 10, d. 15, e. 20
Output (English): c