Simple interest on a sum at 4% per annum for 2 years is Rs.80. The C.I. on the same sum for the same period is?  Pick one.
A) 81.6  B) 81.7  C) 81.0  D) 281.6  E) 81.2
SI = 40 + 40   CI = 40 + 40 + 1.6 = 81.6.81.6nswer: 81.6
<result>A</result>
Simple interest on a sum at 4% per annum for 2 years is Rs.80. The C.I. on the same sum for the same period is?