Question

Ram invests two sum of money $A$ and $B$ at $10\%$ p.a. and $20\%$ p.a respectively at CI for $2$ years. If the total interest on both the sum is Rs$5350$ then find the sum invested in $A$ if the total sum of $A$ and $B$ was Rs$20,000$?

Answer 1

Given : Interest rate for sum A= 10%

Interest rate for sum B = 20%

Total sum = Rs. 20,000

Combined interest = RS 5,350

$\therefore a+b=20,000$ ______________(1)

Total interest = PRT = 2(10% a+20%b)

$\Rightarrow 5350=\frac{2(10a+20b)}{100}=\frac{2(a+2b)}{10}$

$\Rightarrow a+2b=26,750$ ___________ (2)

equation (2) - equation (1) $\Rightarrow a+2b-a-b=26750-20,000$

$\Rightarrow b=6750$

Put b=6750 in (1) we get

$a=20,000-b=20,000-6750$

$=Rs.13250$

$\therefore$ sum interested in A = Rs.13250