If 15% of 30% of 50% of a number is 99, then what is the number?  Choose the correct choice from the following.
A) 4000 B) 3050 C) 4400 D) 4500 E) none of these

Rationale: let the number be a given , 15 / 100 * 30 / 100 * 50 / 100 * a = 99 = > 3 / 20 * 3 / 10 * 1 / 2 * a = 99 = > a = 10 * 20 * 10 * 2 = 4400 . answer : c
Answer: C