A certain sum becomes Rs. 1020 in 5 years and Rs. 1200 in 8 years at simple interest. What is the value of principal? 

The simple interest on an amount of 2,800 at the end of 3 years is Rs 420. What will be the simple interest at Rs 3200 for the same rate and for the same period?

Mohit borrowed Rs. 22000 at 5% simple interest repayable in 5 equal installments. What will be the annual installment payable by him?

The simple interest accrued on an amount of Rs 16500 at the end of 3 years is Rs. 4950. What would be the compound interest accrued on the same amount at the same rate in the same period? 

A certain sum of money lent out at simple interest amounts to Rs. 2400 in 4 years and Rs. 3000 in 6 years. Find the rate of interest per annum?

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.

The simple interest on a certain sum of money at the rate of 5 % per annum for 8 years is ₹ 840. Rate of interest for which the same amount of interest can be received on the same sum after 5 years is? 

A person invested a sum of Rs. 18,600 at x% per year and another sum that is twice the former at (x+2)% per year, both at simple interest. If the total interest earned on both investments for $$ {3{1\over 2}}$$ years is Rs.23,110.50, then the rate of  interest per year on the second investment is: