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

The simple interest on a certain sum of the money at 4 % per annum for 4 years is Rs.80 more than the interest on the same sum for 3 years at 5 % per annum. Find the sum.

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

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-

What equal installment of annual payment will discharge a debt which is due as ₹ 848 at the end of 4 years at 4 % per annum simple interest? 

Rs. 1,080 invested for 3 months gave an interest of Rs. 27. The simple rate of interest per annum was :

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?

A sum of money was invested at a certain rate of simple interest for 2 years. Had it been invested at 1% higher rate, it would have fetched Rs.192 more interest. The sum of money is-