What would be the $C.I.$ obtained on an amount of $Rs. 12000$ at the rate of $9 \,p.c.p.a$ for $3$ years (in $Rs.$)?

$A$ sum of money at compound interest doubles itself in $15$ years. It will become eight times of itself in (in $years$):

On what sum will the compound interest (in ₹) for $2 \frac{1}{2}$ years at $10 \%$ per annum amount to ₹ $6352.50$?

Divide $Rs. 2602$ between $X$ and $Y$,so that the amount of $X$ after $7 \,yr$ is equal to the amount of $Y$ after $9 \,yr$,the interest being compounded at $4 \%$ per annum.

The value of a machine depreciates at the rate of $12\%$ per annum. It was purchased $3$ years ago. Its present value is $Rs. 29644.032$. What was the purchase price (in $Rs.$) of the machine?

If the difference between $S.I.$ and $C.I.$ for $2$ years on a sum of money lent at $5 \%$ per annum is $₹ 6$,then the sum is: