If the difference between the simple interest on a certain sum for $4$ $years$ at $2 \frac{1}{2} \%$ per annum and the simple interest on the same sum for the same period at $3 \%$ per annum is ₹ $60$,then the sum (in ₹) is:

$A$ sum of money doubles itself in $8$ years. In how many years will it treble?

$A$ 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 ₹):

The difference between the interest received from two different banks on $₹ 5,000$ for $2$ $years$ is $₹ 25$. The difference between their rates is (in $\%$):

Arun invested a sum of money at a certain rate of simple interest for a period of $4$ years. Had he invested the same sum for a period of $6$ years,the total interest earned by him would have been $50$ percent more than the earlier interest amount. What was the rate of interest per cent per annum?

What amount (in $Rs.$) would a man have received on a principal of $Rs. 4000$ after $2$ years at a simple interest rate of $5$ $p.c.p.a.$?