A person borrows Rs. 9000 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 answers.
A) 100 rs	B) 150 rs	C) 160 rs	D) 180 rs	E) 200 rs
Gain in 2 years =   [(9000*6*2)/100]-[(9000*4*2)/100]    1080-720= 
<gadget id="calculator"> 1080-720</gadget>
<output>360</output>
360   Gain in 1 year=(360/2)= 
<gadget id="calculator">(360/2)</gadget>
<output>180</output>
180 rs   ANSWER:180 rs
<result>D</result>
A person borrows Rs. 9000 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.