The true discount on Rs. 1860 due 3 years hence is Rs. 40. Find the rate per cent ?
10%
12%
5%
15%
Correct Option: A
R = (100 x T.D.) / (P.W. x T) = (100 x T.D.) / [(A - T.D.) x T] = (100 x 60) / (1800 x 3) [ since P.W. = A - T.D.] = 10% ∴ The rate per cent is 10% per annum