The simple interest on a certain sum at $4 \%$ per annum for $2$ years is ₹ $80$. The compound interest (in ₹) on the same sum for the same period is

The difference between compound and simple interest at a certain rate on $Rs. 2000$ at the end of two years is $Rs. 12.8$. The rate of interest (in $\%$) 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?

$A$ 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?

The difference between the compound interest and the simple interest on ₹ $8000$ for $3$ years at $5 \%$ per annum is (in ₹):

$A$ man borrows $Rs. 5100$ to be paid back with compound interest at the rate of $4 \%$ p.a. by the end of $2$ years in two equal yearly instalments. How much (in $Rs.$) will be each instalment?