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

The amount of Rs 400 becomes Rs 480 in 4 years. If the rate of interest is increased by 2 percent, how much will it be?

At what simple rate of interest a sum is double in 8 years?

If the difference of interest of two banks of Rs 500 is Rs 2.50, find the difference between their rates.

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?

If the simple interest on ₹ 1 for 1 month is 1 paisa, then the rate percent per annum will be 

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

A person invests money in three different schemes for 6 years, 10 years and 12 years at 10%, 12% and 15% simple interest respectively. At the completion of each scheme, he gets the same interest. The ratio of his investments is-