Question

Rs. $1,000$ was invested at $10$% per annum simple interest and a certain sum of money invested at $20$% per annum simple interest. If the sum of the interests on both the sums after $4$ years is Rs. $800$, the latter sum of money is ?

• A. Rs. $450$
• B. Rs. $500$
• C. Rs. $550$
• D. Rs. $600$

Answer 1

The correct option is B Rs. $500$

$1000$ was invested at $10$% p.a. for $4$ years

$S{I}_1=\frac{PRT}{100}\times \frac{1000\times 10\times 4}{100}=400$

Another certain amount P was invested at $20$% p.a. for $4$ years

$S{I}_2=\frac{P\times 20\times 4}{100}=\frac{4P}{5}$

Given, $S{I}_1+S{I}_2=800$

$\Rightarrow 400+\frac{4P}{5}=800$

$4P=2000$

$P=500$

$\therefore$The latter sum of money is Rs.$500$