how many positive integers less than 1960 are such that the product of their digits is 10.  Choose the correct choice from the following:
A) 220 B) 230 C) 280 D) 220 E) 240

Rationale: "1960 is divisible by 10 ( or 2 * 5 ) = 196 196 is divisible by 4 = > 49 49 = 7 * 7 hence 1960 is divisible by 2 , 4,5 , 7 , 7 if there were only one 7 , i . e if the problem were 280 c"
Answer: C