The difference between the compound interest and the simple interest accrued on an amount of ₹ $18000$ in $2$ years was ₹ $405$. What was the rate of interest per cent per annum?

The least number of completed years in which a sum of money put out at $20 \%$ $C.I.$ will be more than doubled is

If in a certain number of years,₹ $3000$ amounts to ₹ $4320$ at compound interest,in half that time ₹ $3000$ will amount to (in ₹):

The simple interest on a certain sum of money for $3$ years at $8 \%$ per annum is half the compound interest on ₹ $4000$ for $2$ years at $10 \%$ per annum. The sum placed on simple interest (in ₹) is

If the compound interest on a certain sum for $2$ $years$ at $3 \%$ per annum is $Rs. 101.50$,then the simple interest (in $Rs.$) on the same sum at the same rate and for the same time will be:

What sum of money (in ₹) at compound interest will amount to ₹ $650$ at the end of the first year and ₹ $676$ at the end of the second year?