In how much time (in $years$) will a sum of ₹ $9500$ amount to ₹ $17622.5$ at the rate of $4.5 \%$ per annum at simple interest?

$A$ person has left an amount of ₹ $1,20,000$ to be divided between his two sons aged $14$ years and $12$ years such that they get equal amounts when each attains $18$ years of age. If the amount gets a simple interest of $5 \%$ per annum,the younger son's share at present (in ₹) is

$A$ sum of ₹ $16800$ is divided into two parts. One part is lent at a simple interest rate of $6 \%$ per annum and the other at $8 \%$ per annum. After $2$ years,the total amount received is ₹ $19000$. The sum lent at the rate of $6 \%$ simple interest (in ₹) is:

$A$ 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

Heena invests an amount of $10250$ at $4$ $p.c.p.a.$ to obtain a total amount of $Rs. 12710$ on simple interest after a certain period. For how many years did she invest the amount to obtain the total sum?

The rate percent per annum at which ₹ $1200$ amounts to ₹ $1440$ in $4$ years is: