What is the difference between the compound interests (in ₹) on ₹ $5000$ for $1 \frac{1}{2}$ years at $4 \%$ per annum compounded yearly and half-yearly?

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 $Rs. 2000$.

The compound interest on a certain sum of money for $2$ years at $5 \%$ per annum is ₹ $410$. The simple interest (in ₹) on the same sum at the same rate and for the same time is:

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

What is the difference between the simple and the compound interest (in ₹) on ₹ $7,300$ at the rate of $6$ $p.c.p.a.$ in $2$ years?

If the amount is $6 \frac{1}{4}$ times the principal after $2$ years at compound interest,the rate of interest (in $\%$) per annum is