A man had 16000 Rs., part of which he lent at 4% and the rest at 5% per annum simple interest. If the total interest received was 700 Rs. In one year, the money lent at 4% per annum was :
[A]6000 Rs.
[B]8000 Rs.
[C]10000 Rs.
[D]12000 Rs.

10000 Rs.
Let the sum lent at 4% = Rs. x
∴ Amount at 5% = 16000 – x
According to the question,
$\frac{x\times 4\times 1}{100}+\frac{(16000-x)\times 5\times 1}{100} = 700$
$=> 4x + 80000-5x = 70000$
$=> x = 80000 - 70000 = 10000$
Hence option [C] is correct answer.