A trader sells 40 metres of cloth for Rs.8200 at a profit of Rs.20 per metre of cloth. How much profit will the trder earn on 40 metres of cloth? Choose the correct choice from the following:
A) rs . 800
B) rs . 1500
C) rs . 1000
D) rs . 1200
E) none of these

Rationale: "explanation : sp of 1 metre cloth = 8200 / 40 = rs . 205 . cp of 1 metre cloth = rs . 205 – 20 = rs . 185 cp on 40 metres = 185 x 40 = rs . 7400 profit earned on 40 metres cloth = rs . 8200 – rs . 7400 = rs . 800 . answer : option a"
Answer: A