Answer with Explanation:

S.I. on Rs. 1600 = T.D. on Rs. 1680.

 Rs. 1600 is the P.W. of Rs. 1680, i.e., Rs. 80 is on Rs. 1600 at 15%.

 Time = (100 x 80 / 1600 x 15) year = 1/3 year = 4 months.

back