1.  At what rate percent per annum will the simple interest on a sum of money be of the amount in 10 years ?
A. 4%
B. 52/3%
C. 6%
D. 62/3%

Answer: Option A

Explanation:

Let sum = X. Then,
S.I. = 2X / 5 , Time = 10 years.

Rate = 100 x 2X % = 4%
X x 5 x 10