In how many years will ₹ $150$ produce the same interest at $8 \%$ per annum as ₹ $800$ produces in $3$ years at $4 \frac{1}{2} \%$ per annum?

What is the interest (in $Rs.$) received on a principal of $Rs. 450$ for $2$ years, if the interest received on $Re. 1$ after $4$ years at the same rate of simple interest is $Rs. 0.40$?

The simple interest accrued on an amount of ₹ $22,500$ at the end of four years is ₹ $10,800$. What would be the compound interest accrued on the same amount (in ₹) at the same rate of interest at the end of two years?

At what percent of simple interest will a sum of money double itself in $15$ years?

$A$ sum of ₹ $26000$ was lent out in two parts in such a way that the interest on one part at $10 \%$ for $5$ $years$ is equal to that on the other part at $9 \%$ for $6$ $years.$ The sum lent out at $10 \%$ is (In ₹)

$A$ man took a loan from a bank at the rate of $12 \%$ $p.a.$ simple interest. After $3$ $years$ he had to pay ₹ $5400$ interest only for the period. The principal amount (in ₹) borrowed by him was: