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 - 

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. 

A sum of ₹ 1750 is divided into two parts such that the interests on the first part at 8 % simple interest per annum and that on the other part at 6 % simple interest per annum are equal. The interest on each part (in rupees) is 

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

If certain sum, at simple interest turns into thrice of actual amount in 4 years. Find out time to become the amount thirteen times of initial amount? 

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 person lends 40 % of his sum of money at 15 % per annum, 50 % of rest at 10 % per annum and the rest at 18 % per annum rate of interest. What would be the annual rate of interest, if the interest is calculated on the whole sum?