Bindu lends $Rs. 10000$ in four parts to her friends. If she gets $8 \%$ on $Rs. 2000$,$7.5 \%$ on $Rs. 4000$ and $8.5 \%$ on $Rs. 1400$,what percent must she get for the remainder,if the average interest is $8.13 \%$?

If the simple interest on a certain sum of money after $6 \frac{1}{4}$ years is $\frac{3}{8}$ of the principal,then the rate of interest (in $\%$) per annum is

Kavita invested $\frac{1}{3}$ of her money at $4 \% \text{ p.a.}$,$\frac{1}{4}$ at $3 \% \text{ p.a.}$,and the rest at $5 \% \text{ p.a.}$ She received an annual interest of $Rs. 500$ on her money. Find the total money invested (in $Rs.$).

Mayuri took a loan at a simple interest rate of $6 \, p.c.p.a.$ in the first year,and the rate increased by $1.5 \, p.c.p.a.$ every year. If she paid $Rs. 8190$ as interest at the end of $3 \, years$,what was her loan amount (in $Rs.$)?

$A$ 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

$A$ 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