A person borrows Rs. 6000 for 2 years at 4% p.a. simple interest. He immediately lends it to another person at 6 p.a for 2 years. Find his gain in the transaction per year.  Select
A) 120 rs  B) 150 rs  C) 160 rs  D) 180 rs  E) 200 rs

Rationale: "gain in 2 years = [ ( 6000 * 6 * 2 ) / 100 ] - [ ( 6000 * 4 * 2 ) / 100 ] 720 - 480 = 240 gain in 1 year = ( 240 / 2 ) = 120 rs answer : a"
Answer: A