How much interest will be received in 2.5 years at the rate of 4 percent simple interest of Rs. 3,680?

How much simple interest will be received in 10 years on the amount of Rs. 1600? If the rate of interest is 7.25 percent per annum.

At the rate of 8 % simple annual interest, if an amount becomes Rs. 819 in 3 years and 3 months, then what was the original amount?

The simple interest of 7 years of money is Rs. 1750. If the rate of interest was 2% more per annum, how much interest would have been higher?

A sum of money at double the rate of simple interest doubles itself in 10 years. In how much time will that amount be triple of itself?

An amount doubles itself in 5 years with simple interest. What is the rate of interest per year?

Some amount out of Rs.7000 was lent at 6% per annum and the remaining at 4% per annum. If the total simple interest from both the fractions in 5 year was Rs.1600, find the sum lent at 6% per annum.

A sum is to be paid back in 3 equal annual instalments. The interest is compound annually at 30% per annum. If each instalment be Rs.21970 then what is the sum?