Question : The difference between simple interest on a certain sum at the annual rate of 8 percent for 5 years and 6 years is Rs. 26. What is the sum?

Question : A certain sum becomes 4 times of itself in 5 years at a rate of simple interest. In 15 years it will become how many times of itself at the same rate of simple interest?

Question : The simple interest accrued on a certain principal is Rs. 1200 in 3 years at 8% per annum. What would be the compound interest (compounding annually) accrued on twice that principal at 10% per annum in 2 years?

Question : Rs. P is invested at 5% per annum at simple interest. After $T$ years an interest of Rs. 82 is earned and the amount becomes Rs. 902. What is the value of $T$?

Question : At a certain sum of money with the interest rate of 6% per annum for 4 years, the simple interest is Rs. 4500. Find the compound interest (compounding annually) of 2 years at the same sum when the rate of interest is 4% per annum.