Compound Interest Ques 8
Question
Yash invests Rs. 1200 in scheme A, which offers a compound interest (on an annual basis) at a rate of $20 \%$ p.a. for a period of 2 years. He invests a certain sum in scheme B, which offers simple interest at a rate of $15 \%$ p.a. for a period of 3 years. The interest received from scheme A is Rs. 42 more than that received from scheme $B$. The sum invested in scheme B was what per cent of that invested in scheme A ?
(1) 90
(2) 110
(3) 80
(4) 75
(5) 25
(Bank of Maharashtra PO Exam, 26.10.2016)
Show Answer
Answer: (1)
Solution: (1)
C.I. received from scheme A $=P\left[\left(1+\frac{R}{100}\right)^{T}-1\right]$
$=1200\left[\left(1+\frac{20}{100}\right)^{2}-1\right]$
$=1200\left[\left(\frac{6}{5}\right)^{2}-1\right]$
$=1200\left(\frac{36}{25}-1\right)$
$=1200\left(\frac{36-25}{25}\right)$
$=1200 \times \frac{11}{25}=$ Rs. 528
Investment in scheme B $=$ Rs. $x$ (let)
$\therefore$ S.I. $=\frac{\text { Principal } \times \text { Time } \times \text { Rate }}{100}$ $=\frac{x \times 3 \times 15}{100}=$ Rs. $\frac{45 x}{100}$
According to the question,
$\frac{45 x}{100}=528-42=486$
$\Rightarrow x=\frac{486 \times 100}{45}=$ Rs. 1080
$\therefore$ Required per cent $=\frac{1080}{1200} \times 100=90 \%$
BETA
