The cost of the paint is rs.50 per kg. if 1kg of paint covers 20 sq.ft, how much will it cost to paint outside of a cube having 20 feet each side
Choose the correct choice:  A) rs . 962  B) rs . 6000  C) rs . 546  D) rs . 876  E) none of these

Rationale: "explanation : surface area of a cube = 6 x 20 ^ 2 = 2400 sq . ft quantity of paint required = ( 2400 / 20 ) = 120 kg cost of painting = 50 x 120 = rs . 6000 answer : b"
Answer: B