A sports equipment store sold ping pong rackets for a total of $686. If the average (arithmetic mean) price of a pair of rackets is $9.8, how many pairs were sold?
Choose the correct choice from the following options
A) 50 B) 100 C) 70 D) 500 E) 980

Rationale: average price for a pair of rackets = $ 9.8 total cost = $ 9.8 * x = $ 686 x = 70 pairs were sold . answer : c
Answer: C