A man gets a simple interest of $Rs. 1000$ on a certain principal at the rate of $5$ $p.c.p.a.$ in $4$ years. What compound interest (In $Rs.$) will the man get on twice the principal in two years at the same rate?

Sam invested ₹ $15000$ at $10 \%$ per annum for one year. If the interest is compounded halfyearly, then the amount (In ₹) received by Sam at the end of the year will be

A sum of money, deposited at some rate $p.c.p.a.$ of compound interest, doubles itself in $4$ years. In how many years will it become $16$ times of itself at the same rate?

A man borrows ₹ $25000$ at $20 \%$ compound interest. At the end of every year he pays ₹ $5000$ as part repayment. How much (In ₹) does he still owe after three such instalments?

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 percent per annum is

An amount of money at compound interest grows up to ₹ $3,840$ in $4$ years and up to ₹ $3,936$ in $5$ years. Find the rate of interest (In $\%$)