If X represents the product of the first 15 positive integers, then X is not a
multiple of:  Choose the correct choice.
A) 99 B) 84 C) 72 D) 57 E) 67

Rationale: a ) 99 = 9 * 11 b ) 84 = 4 * 7 * 3 c ) 72 = 9 * 11 d ) 65 = 5 * 13 e ) 57 = 19 * 3 since 19 is not there in first 15 positive numbers it is the only possibility d )
Answer: D