An amount of Rs 8500 becomes Rs 9500 in 3 years at some simple rate of interest. How much will an amount of Rs 10200 become in 5 years at the same rate of simple interest?

The amount becomes Rs 12200.

Interest on 8500 in 3 years = 9500 - 8500 = 1000.

SI per rupee per year = 1000 / (8500 x 3).

For 10200 over 5 years: SI = 10200 x 5 x 1000 / (8500 x 3) = 2000.

Amount = 10200 + 2000 = 12200.

Method: keep the rate fixed and scale principal and time.