Asif borrows Rs. 1500 from two moneylenders. He pays interest at the rate of 12% per annum for one loan and at the rate of 14% per annum for the other. The total interest he pays for the entire year is Rs. 186. How much does he borrow at the rate of 12%

Correct Answer: Rs. 1200
Let Asif lent Rs. X at 14% per year.
Hence, Money lent at 12% = (1500 - x);
Given, total interest = Rs. 186
$$ {\frac{{\left( {x \times 14 \times 1} \right)}}{{100}}} \, + $$    $$ {\frac{{\left}}{{100}}} $$      = 186
$$\eqalign{ & \frac{{14x}}{{100}} + \frac{{ {18000 - 12x} }}{{100}} = 186 \cr & 14x + 18000 - 12x = 186 \times 100 \cr & 2x = 18600 - 18000 \cr & x = \frac{{600}}{2} = {\text{Rs}}{\text{. }}300 \cr & {\text{Hence, money lent}}{\kern 1pt} {\text{at }}12\% \cr & = 1500 - 300 \cr & = {\text{Rs}}{\text{.}}\,1200 \cr} $$