The difference between the simple and compound interest on a certain sum of money for $2$ years at $4 \%$ per annum is $Rs. 4$. Find the sum (In $Rs.$)?

Suneeta borrowed a certain sum from Reena for $2 \,yr$ at simple interest. Suneeta lent this sum to Venu at the same rate for $2 \,yr$ at compound interest. At the end of $2 \,yr$,she received $Rs. 110$ as compound interest but paid $Rs. 100$ as simple interest. Find the sum and the rate of interest.

What would be the $C.I.$ obtained on an amount of $Rs. 4800$ at the rate of $5$ $p.c.p.a$ for $3$ years (in $Rs.$)?

If a sum of money placed at compound interest,compounded annually,doubles itself in $5$ years,then the same amount of money will be $8$ times of itself in how many years?

What will be the compound interest (in ₹) on a sum of ₹ $1875$ after $2$ years if the rate of interest for the first year is $4 \%$ and that for the second year is $8 \%$?

Find the present worth (in ₹) of ₹ $9261$ due $3$ years hence at $5 \%$ per annum compounded yearly.