The width of a rectangular hall is ½ of its length. If the area of the hall is 200 sq.m, what is the difference between its length and breadth?  Select the correct option
A) 8 m B) 10 m C) 12 m D) 15 m E) 17 m

Rationale: let the length of the hall be x m breadth of the hall = 1 x / 2 m area of the hall = length * breadth 200 = x * 1 x / 2 x ² = 400 x = 20 difference between the length and breadth of the hall = x - 1 x / 2 = x / 2 = 20 / 2 = 10 m answer : b
Answer: B