The difference between simple and compound interest on Rs. 1600 for one year at 10% per annum reckoned half-yearly is? Pick one.
A) 8  B) 3  C) 9  D) 4  E) 2

Rationale: "s . i . = ( 1600 * 10 * 1 ) / 100 = rs . 160 c . i . = [ 1600 * ( 1 + 5 / 100 ) 2 - 1600 ] = rs . 164 difference = ( 164 - 160 ) = rs . 4 . answer : d"
Answer: D