1.  The simple interest and the true discount on a certain sum for a given time and at a given rate are Rs. 85 and Rs. 80 respectively. The sum is:
A. Rs. 1800
B. Rs. 1450
C. Rs. 1360
D. Rs. 6800

Answer: Option C

Explanation:

Sum = S.I. x T.D. = 85 x 80 = Rs. 1360.
(S.I.) - (T.D.) (85 - 80)