A person invested some amount at the rate of 12% simple interest and the remaining at 10%. He received yearly an interest of Rs. 130. Had he interchanged the amounts invested, he would have received an interest of Rs. 134. How much money did he invest at different rates?
Rs. 500 at the rate of 10%, Rs 800 at the rate of 12%
Rs. 700 at the rate of 10%, Rs 600 at the rate of 12%
Rs. 800 at the rate of 10%, Rs 400 at the rate of 12%
Rs. 700 at the rate of 10%, Rs 500 at the rate of 12%
Solution
Suppose the person invested Rs. $x$ at the rate of 12% simple interest and Rs. $y$ at the rate of 10% simple interest, then yearly interest $= \dfrac{12x}{100}+ \dfrac{10y}{100}$
$\dfrac{12x}{100} + \dfrac{10y}{100} = 134.....(i)$
Similarly $\dfrac{10x}{100} + \dfrac{12y}{100} = 134.....(ii)$
From (i) and (ii)
$x = 500$ and $y = 700$
A person invested Rs. 700 at the rate of 10% and 500 at the rate of 12% per year.