$A$ sum of ₹ $15000$ deposited at compound interest becomes double after $5$ $years$. After $20$ $years$,it will become (in ₹):

In how many years will ₹ $2,000$ yield ₹ $662$ as compound interest at $10 \%$ per annum compounded annually?

$A$ certain sum of money (in $Rs.$) gives $Rs. 500$ as Simple Interest $(S.I.)$ at $5 \%$ per annum for $1$ year. What is the Compound Interest $(C.I.)$ on the same sum at the same rate at the end of $2$ years?

Suneeta borrowed a certain sum from Reena for $2 \,yr$ at simple interest. Suneeta lent this sum to Venu at the same rate for $2 \,yr$ at compound interest. At the end of $2 \,yr$,she received $Rs. 110$ as compound interest but paid $Rs. 100$ as simple interest. Find the sum and the rate of interest.

The simple interest accrued on an amount of $Rs. 20000$ at the end of $3$ years is $Rs. 7200$. What would be the compound interest accrued on the same amount at the same rate in the same period?

The compound interest on a certain sum for $2$ years at $10 \%$ per annum is ₹ $525$. The simple interest (in ₹) on the same sum for double the time at half the rate per cent per annum is