Find the least number of complete years in which a sum of money put out at the rate of 20% per annum compound interest will be more than double.

A sum of money doubles itself in 15 years at compound interest. In how many years it will become 8 times at the same compound interest rate?

A sum of money lent at compound interest for 2 years at 20% per annum would earn ₹482 more, if the interest was payable half yearly than if it was payable annually. The sum is

There is 60% increase in an amount in 6 years at simple interest. What will be the compound interest (in ₹) on ₹12,000 after 3 years at the same rate of interest?

In what duration of time will ₹3300 become ₹3399 at 12% per annum interest compounded quarterly?

A sum of ₹16,800 was taken as a loan. This is to be paid in two equal instalments. If the rate of interest is 10% per annum compounded annually, then the value of each instalment (in ₹) is