The simple interest on ₹ 4,000 in 3 years at the rate of x % per annum equals the simple interest on ₹ 5,000 at the rate of 12% per annum in 2 years. The value of x 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. 

The simple interest of 7 years of money is Rs. 1750. If the rate of interest was 2% more per annum, how much interest would have been higher?

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? 

What is the ratio of the simple interest earned on a certain amount at the rate of 21% per annum for 8 years to that earned on the same sum at the same rate for 21 years?  

A certain amount of money earns Rs. 540 as simple interest in 3 years. If it earns a compound interest of Rs. 376.20 at the same rate of interest in 2 years, find the amount.

Find the simple interest on a principal of Rs.1250 at the rate of 5% for a time of 219 days.

The difference between C.I and S.I for 2 years is Rs. 9. Find the sum (in Rs.) if the rate is 15% per annum.