The length of a rectangular floor is more than its breadth by 200%. If Rs. 624 is required to paint the floor at the rate of Rs. 4 per sq m, then what would be the length of the floor?  Options.
A) 22.8 m . B) 21.6 m . C) 21.1 m . D) 20.6 m . E) 22.5 m .

Rationale: "let the length and the breadth of the floor be l m and b m respectively . l = b + 200 % of b = l + 2 b = 3 b area of the floor = 624 / 4 = 156 sq m l b = 156 i . e . , l * l / 3 = 156 l 2 = 468 = > l = 21.6 m . answer : b"
Answer: B