A bank offers 5% compound interest calculated on half-yearly basis. A customer deposits $ 1600 each in 1st month and 7th month of a year. At the end of the year, the amount he would have gained by way of interest is?
Choose one:	A) 121	B) 50	C) 100	D) 160	E) 80
Amount = (1600)* (1 + (5/2*100))^2   Amount = 1600 * (41/40) * (41/40)= 
<gadget id="calculator">1600 * (41/40) * (41/40)</gadget>
<output>1_681</output>
1681 ------(for investment in 1st month) Amount= 1600 * (41/40)= 
<gadget id="calculator">1600 * (41/40)</gadget>
<output>1_640</output>
1640 -----(for investment in 7th month) Total Amount= 1681 + 1640= 
<gadget id="calculator">1681 + 1640</gadget>
<output>3_321</output>
3321 Interest= 3321-3200 = 121.............. 121ns -121
<result>A</result>
A bank offers 5% compound interest calculated on half-yearly basis. A customer deposits $ 1600 each in 1st month and 7th month of a year. At the end of the year, the amount he would have gained by way of interest is?