A person borrows Rs. 8000 for 2 years at 4% p.a. simple interest. He immediately lends it to another person at 6 p.a for 2 years. Find his gain in the transaction per year.  Choose the correct choice from the following choices:
A) 100 rs
B) 150 rs
C) 160 rs
D) 180 rs
E) 200 rs
Gain in 2 years =   [(8000*6*2)/100]-[(8000*4*2)/100]    960-640= 
<gadget id="calculator"> 960-640</gadget>
<output>320</output>
320   Gain in 1 year=(320/2)= 
<gadget id="calculator">(320/2)</gadget>
<output>160</output>
160 rs   ANSWER:160 rs
<result>C</result>
A person borrows Rs. 8000 for 2 years at 4% p.a. simple interest. He immediately lends it to another person at 6 p.a for 2 years. Find his gain in the transaction per year.