Question

At a certain rate of interest, the interest after 4 years on 5000 rupees principal is 1200 rupees. What would be the interest of 15000 rupees at the same rate of interest for the same period? If Pankaj deposits 1,50,000 rupees in a bank at 10 p.c.p.a. for two years, what is the total amount he will get from the bank

Answer 1

Interest on $5000$ after $4$ years $=\frac{\left(5000\right)\left(4\right)r}{100}=200r$

where $r=$ rate of interest

Given $200r=1200$

$\Rightarrow r=6$

$\therefore$ Rate of interest $=6\%$

Interest on $15000$ rupees $=\frac{pnr}{100}$

$=\frac{15000\times 4\times 6}{100}$

Interest on $15,000$ $=600\times 6=Rs3600$.

Pankaj Invested amount P$=1,50,000$

Interest $=10\%=r$

No. of years $=n=2$

Total amount he gets after $2$ years $=P+\frac{Pnr}{100}$

$=P[1+\frac{2\times 10}{100}]$

$=P\left(\frac{6}{5}\right)=150000\times \frac{6}{5}$

$=1,80,000$

$\therefore$ Pankaj gets Rs. $1,80,000$ after $2$ years.