Simple and Compound Interest

The simple interest and compound interest on a sum of money for 2 years are Rs. 1800 and Rs. 1890 respectively. So, at what interest rate was that sum kept?

Amit had invested same amount of sums at simple as well as compound interest, compounded annually. The time period of investment for both the sums was 2 years and rate of interest too was the same, 4% per annum. At the end, he found a difference of ₹43 in both the interests received. What were the sums (in ₹) invested?

A borrows Rs. 89,500 for 3 years at 7% p.a. simple interest. B borrows the same amount at 9% simple interest for the first year, 8% for the second year, and 7% for the third year. What is the total simple interest (in Rs.) paid by A and B?

Rs. 11,340 is the simple interest generated when a certain amount of money is lent at the rate of 9% per annum for 6 years. Find the amount that will be paid after 6 years.

The simple interest on a certain sum is ₹1200 in 4 years at the rate of 8% per annum. What will be the simple interest on three times that principal in 3 years at 6% per annum?

Ana has invested $1000 in a savings account so that it would be doubled after 10 years. If the interest on the account is compounded annually, what annual interest rate is necessary for this to happen?

The sum is invested at the simple interest payable annually. The interest in two successive years, starting from first year, was Rs. 500 and Rs. 540. Find the sum.

The difference between compound interest and simple interest on a sum for 2 years at the same 6% interest per annum is Rs. 36. Then, that sum (in rupees) is

Mr. X borrows Rs. 500000 and repays the principal over the next 20 years in equal installments along with the interest accrued for the year. What amount would he have to pay as simple interest every year if the rate of interest is 10% p.a?