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?

The compound interest on a sum of money for $3$ years at $5 \%$ per annum is ₹ $1324.05$. What is the simple interest (in ₹)?

An amount of ₹ $12500$ is deposited for a period of $2$ years at an interest rate of $4 \%$ per annum. Find the difference between the simple interest and the compound interest (in ₹) for the deposit.

Abhinav invested a certain amount at the rate of $8$ $p.c.p.a.$ for $5$ years and obtained a $SI$ of $Rs. 3800$. Had he invested the same amount at the same interest rate for $2$ years,how much amount (in $Rs.$) would he have obtained as $CI$ at the end of $2$ years?

Which of the statements given below are sufficient to answer the following question?
What is the rate of interest per annum on an investment of $Rs. 800$?
$(I)$ The income from $S.I.$ at the end of $3$ years at the same rate of interest is $19$.
$(II)$ $C.I.$ is $15.76$ more than $S.I.$ on the same sum and same rate in $2$ years.

Nikita invested ₹ $8000$ for $3$ years at $5 \%$ $C.I.$ in a post office. If the interest is compounded once in a year,what sum (in ₹) will she get after $3$ years?