$A$ certain sum becomes $5$ times in $3$ years at simple interest. In how many years will it become $13$ times?

$A$ lent ₹ $5,000$ to $B$ for $2$ years and ₹ $3,000$ to $C$ for $4$ years on simple interest at the same rate of interest and received ₹ $2,200$ in all from both of them as interest. The rate of interest (in $\%$) per annum is:

If a certain sum of money amounts to ₹ $1760$ in $2$ years and ₹ $2000$ in $5$ years at simple interest,then the sum (in ₹) is:

Mr. Gupta deposits ₹ $3000$ in a bank at $10 \%$ $p.a.$ and ₹ $5000$ in another bank at $8 \%$ $p.a.$. The rate of interest (in $\%$) for the whole sum is

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 sum lent at $10 \%$ per year on $S.I.$ will amount to $Rs. 450$ in $2$ years?