A certain sum at compound interest amounts in two years to ₹ $2809$ and in three years to ₹ $2977.54 .$ Find the rate of interest and the original sum (In ₹).

A sum of $Rs. 8448$ is to be divided between $X$ and $Y$ who are respectively $18$ and $19 \,yr$ old, in such a way that if their shares be invested at $6.25 \%$ per annum at compound interest, they will receive equal amounts on attaining the age of $21 \,yr$. The present share of $X$ is (In $Rs.$)

A certain sum of money invested at compound interest becomes $1.44$ times of itself in $2$ years. If twice this sum were lent at simple interest, in how many years would it double itself?

The difference between simple and compound interest on sum of $10000$ is $64$ for $2$ years. Find the rate of interest.

A sum put out at $4 \%$ compound interest payable half-yearly amounts to ₹ $6632.55$ in $1 \frac{1}{2}$ years. The sum (In ₹) is

Which information given below is sufficient to know the amount if the difference between the $C.I. \& S.I.$ for $2$ years is $18$?

($I$) The rate is same at which an amount of $Rs. 1000$ become $1120$ for $2$ years in $S.I.$

($II$) The principal given is $Rs. 2000$.