The ratio between the length and the breadth of a rectangular park is 1 : 2. If a man cycling along the boundary of the park at the speed of 6 km/hr completes one round in 6 min, then the area of the park (in sq. m) is? Choices.
A) 600 m  B) 6000 m  C) 20000 m  D) 100 m  E) 2000 m

Rationale: "perimeter = distance covered in 6 min . = ( 6000 x 6 ) / 60 m = 600 m . let length = 1 x metres and breadth = 2 x metres . then , 2 ( 1 x + 2 x ) = 600 or x = 100 . length = 100 m and breadth = 200 m . area = ( 100 x 200 ) m 2 = 20000 m c"
Answer: C