What would be the compound interest drawn on an amount of Rs. $18,400$ at the rate of $12$ p.c.p.a. at the end of $3$ years?

The compound interest on a certain sum for $2$ years at $10\%$ per annum is Rs. $525$. The simple interest on the same sum for double the time at half the rate of interest per annum is:

Abhijit borrowed Rs. $15,000$ from Nisha at compound interest rate of $12$ p.c.p.a. How much money should Abhijit pay at the end of $2$ years to settle the loan?

If the compound interest on a sum for $2$ years at $12\frac{1}{2}\%$ per annum is Rs. $510$, the simple interest (in Rs.) on the same sum at the same rate for the same period of time is: