1.  Find the rate percent if the banker’s gain on a certain sum due two and a half year hence is 1/5 of the banker’s discount.
A. 12.5%
B. 15%
C. 10%
D. 7.5%

Answer: Option C

Explanation:

Let B.D. be Re. 1.

Then, B.G. = Rs. 10 = Rs. 2.
5

T.D = (B.D - B.G) = (10 - 2) = Rs. 8.


Sum = Rs. 10 x 8 = Rs. 80 = Rs. 40.
10 - 8 2

S.I. on Rs. 40 for 2.5 years is Rs. 10

Rate = 100 x 10 % = 10%.
40 x 2.5