What will be the compound interest on a sum of ₹ $25000$ after $3$ years at the rate of $12 \%$ per annum?

Which information given below is sufficient to know the principal amount if the difference between the $C.I.$ and $S.I.$ for $2$ years is $18$?
$(I)$ The rate is same at which an amount of $Rs. 1000$ becomes $1120$ in $2$ years under $S.I.$
$(II)$ The principal is $Rs. 2000$.

Sita deposited $Rs. 5000$ at $10\%$ simple interest for $2$ years. How much more money (in $Rs.$) will Sita have in her account at the end of $2$ years,if it is compounded semi-annually?

If the difference between $S.I.$ and $C.I.$ is $Rs. 25$ on $10000$ for $2$ years,then what is the rate of interest (in $\%$)?

If the simple interest on a sum of money for $2$ years at $5 \%$ per annum is ₹ $50$,what is the compound interest (in ₹) on the same sum at the same rate and for the same time?

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?