Reena took a loan of $. 1200 with simple interest for as many years as the rate of interest. If she paid $ 432 as interest at the end of the loan period, what was the rate of interest?  Answers: A) 3.6 B) 6 C) 18 D) can not be determined E) none of these

Rationale: "let rate = r % and time = r years . then , 1200 x r x r / 100 = 432 12 r 2 = 432 r 2 = 36 r = 6 . answer : b"
Answer: B