The ratio between the length and the breadth of a rectangular park is 1 : 3. If a man cycling along the boundary of the park at the speed of 12 km/hr completes one round in 4 min, then the area of the park (in sq. m) is?	Choose the correct choice from the following options.
A) 800 m B) 12000 m C) 36000 m D) 80000 m E) 30000 m

Rationale: "perimeter = distance covered in 4 min . = ( 12000 x 4 ) / 60 m = 800 m . let length = 1 x metres and breadth = 3 x metres . then , 2 ( 1 x + 3 x ) = 800 or x = 100 . length = 100 m and breadth = 300 m . area = ( 100 x 300 ) m 2 = 30000 m e"
Answer: E