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 annual payment (in $Rs.$) will discharge a debt of $Rs. 770$ due in $5$ years,the rate of interest being $5 \%$ per annum?

$A$ sum was put at simple interest at a certain rate for $2$ years. Had it been put at $1 \%$ higher rate,it would have fetched ₹ $24$ more. The sum is (in ₹):

Albert invested an amount of $x$ rupees in a fixed deposit scheme offering $10 \%$ per annum for the $1^{\text{st}}$ year and $15 \%$ per annum for the $2^{\text{nd}}$ year and received an amount of ₹ $20,240$ after two years. What is $x$ (in ₹)?

In what time (in $years$) will ₹ $1200$ become ₹ $1344$ at $6 \%$ per annum simple interest?

$A$ lends ₹ $2500$ to $B$ and a certain sum to $C$ at the same time at $7 \%$ $p.a.$ simple interest. If after $4$ $years,$ $A$ altogether receives ₹ $1120$ as interest from $B$ and $C,$ then the sum lent (in ₹) to $C$ is