Question

Rs. $6000$ becomes Rs. $7200$ in $4$ years at a certain rate of interest. If the rate becomes $1.5$ times of itself, the amount of the same principal in $5$ years will be

• A. Rs. $8000$
• B. Rs.$8250$
• C. Rs. $9000$
• D. Rs. $9250$

Answer 1

The correct option is B Rs.$8250$

Given, $P=$ Rs. $6000$, Amount $=$ Rs. $7200$, Time $=4$ years
S.I. $=A-P=$ Rs. $7200-$ Rs. $6000$

S.I $=$ Rs. $1200$
$\therefore$ Rate $=\left(\begin{array}{c}\frac{1200\times 100}{6000\times 4}\end{array}\right)\%p.a.=5\%p.a.$
New rate $=1.5\times 5=7.5\%p.a.$
$\therefore$ Required amount $=$ Rs. $6000+$ Rs. $\frac{6000\times 7.5\times 5}{100}$

$=$ Rs. $6000+$ Rs. $2250$
$=$ Rs. $8250$