The true discount on Rs. 3520 due after a certain time at 18% per annum is Rs. 320. The time after which it is due is:
Answer: C
P.W. = Rs. (3520 -320) = Rs. 3200.
S.I. on Rs. 3200 at 18% is Rs. 320.
Time = ( 100*TD)/PW*R= ( 100*320)/3200*18= 5/9 years