At what rate percent per annum simple interest will a sum of money triple itself in 25 years

Mohan borrowed Rs. 16,000 for 3 at 5% per annum compound interest.  Then the amount that Mohan will pay at the end of 3 years?

If S.P of an article is 4/3 of C.P then the profit in the  transaction is 

Interest on Rs. 100 for 1 year is called. 

The population of a town increases 10% every 3 years.  If the present population of the town is 72,600.   Then its population after 6 years is 

At what rate percent compound interest will  Rs. 625 amount to Rs.900 in 2 years 

The compound interest on Rs. 7500 at 8% per annum for 5 years is 

A sum amounts to rs. 1352 in 2 years at 4% compound interest.  The sum is

A sum of amounts to Rs. 1352 in 2 years at 4% compound interest. The sum is

The difference between simple interest and the compound  interest on Rs. 800 at 5% per annum for 1 year is.