1.  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?
A. 3.6
B. 6
C. 18
D. Cannot be determined
E. None of these

Answer: Option B

Explanation:

Let rate = R% and time = R years.

Then, 1200 x R x R = 432
100

12R2 = 432

R2 = 36

R = 6.