If the C.I. on a sum for 2 years at 12 1/2 % per annum is Rs. 510, the S.I. on the same sum at the same rate for the same period of time is________?

A. Rs. 400
B. Rs. 450
C. Rs. 460
D. Rs. 480
Explanation:
Let the sum be Rs. P. Then,
[P(1 + 25/(2 * 100))2 – P] = 510
P[(9/8)2 – 1] = 510.
Sum = Rs. 1920
So, S.I. = (1920 * 25 * 2) / (2 * 100) = Rs. 480