In a certain archery competition, points were awarded as follows: the first place winner receives 11 points, the second place winner receives 7 points, the third place winner receives 5 points and the fourth place winner receives 2 points. No other points are awarded. John participated several times in the competition and finished first, second, third, or fourth each time. The product of all the points he received was 38500. How many times did he participate in the competition?  Choose the correct choice from the following choices
A) 6  B) 7  C) 8  D) 9  E) 10

Rationale: 38500 = 2 * 2 * 5 * 5 * 5 * 7 * 11 john participated 7 times . the answer is b .
Answer: B