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 

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 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?

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?

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.

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.