The simple interest on a sum of money will be Rs.601 after 10 years. If the principal is tribled after 5 years the total interest at the end of 10 years will be

Explanation:

Let the principal be Rs.x

I = Rs.600, N = 10 years

R=100×600\x×10=(6000\x)%

Interest for first 5 years = Rs.x×5×6000\100×x = Rs.300

interest for last 5 years = Rs.3x×5×6000\100×x = Rs 900

Total interest = Rs.300+Rs.900 = Rs.1200