The difference between the simple interest between the simple interest received from two different sources on ₹ 1500 for 3 years is ₹ 13.50. The difference between their rate of interest is - 

If the instalments are paid at the end of every year, what annual payment will discharge a debt of Rs. 7,200 due in 3 years at 20% per annum simple interest?

An amount doubles itself in 5 years with simple interest. What is the rate of interest per year?

The simple interest for four years is one fourth of the principal. At the same rate, which amount become Rs.450 total amount in 2 years?

In how many years will Rs 4600 amount to Rs 5428 at 3 % per annum simple interest?

A sum of Rs. 400 becomes Rs. 448 at simple interest in 2 years. In how many years, will the sum of Rs. 550 amounts to Rs. 682 at the same rate?

A man borrows some amount at the rate of 12% per annum at simple interest. After 6 years 8 months, he paid 720 as an interest. Find the amount borrowed by him.