$A$ sum of ₹ $8000$ is divided into two parts. The simple interest on the first part at the rate of $21 \%$ per annum is equal to the simple interest on the second part at the rate of $35 \%$ per annum. What is the interest (in ₹) of each part?

$A$ sum of ₹ $2800$ is divided into two parts in such a way that the interest on both the parts is equal. If the first part is lent at $9 \% \text{ p.a.}$ for $5 \text{ years}$ and the second part is for $6 \text{ years}$ at $10 \% \text{ p.a.}$,find the two sums.

Reena took a loan of ₹ $1,200$ with simple interest for as many years as the rate of interest. If she paid ₹ $432$ as interest at the end of the loan period,what was the rate of interest?

₹ $800$ becomes ₹ $956$ in $3$ $years$ at a certain rate of simple interest. If the rate of interest is increased by $4 \%,$ what amount (in ₹) will ₹ $800$ become in $3$ $years?$

What time (in years) is taken by a sum of $Rs. 7000$ to become $Rs. 10500$ at the rate of $5 \%$ per annum 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