A principal increase by 50 percent in five years at the rate of simple interest. What will be the compound interest for 3 years at Rs 20,000 with the same interest rate?

A certain sum doubles in 7 years at simple interest. The same sum under the same interest rate will become 4 times in how many years.:

At what annual percentage rate, 10 years of simple interest on an amount will be $$ {2\over 5}$$ of the addition?

The simple interest on a certain sum of the money at 4 % per annum for 4 years is Rs.80 more than the interest on the same sum for 3 years at 5 % per annum. Find the sum.

A sum of Rs.1600 gives a simple interest of Rs.252 in 2 years and 3 months. The rate of interest per annum is 

If the difference between CI and SI for 3 years at the rate of 10% is Rs 31. Find the principle.

The simple interest on an amount at the rate of 13.5 p.c.p.a. for 10 years is Rs. 765.45. What is the sum?

Rs. 1,080 invested for 3 months gave an interest of Rs. 27. The simple rate of interest per annum was :