If A lends Rs.3500 to B at 10% per annum and B lends the same sum to C at 15% per annum then the gain of B in a period of 3 years is? Choose the correct choice from the following choices
A) 525 B) 500 C) 510 D) 530 E) 550

Rationale: "( 3500 * 5 * 3 ) / 100 = > 525 answer : a"
Answer: A