True Discount - General Aptitude

Q1:

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

ANS:C - Rs. 1360

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