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?
Select.
A) 800 m B) 12000 m C) 36000 m D) 80000 m E) 30000 m
Perimeter = Distance covered in 4 min. = (12000 x 4)/60 m = 800 m.   Let length = 1x metres and breadth = 3x metres.   Then, 2(1x + 3x) = 800 or x =100.   Length = 100 m and Breadth = 300 m.   Area = (100 x 300) m2 = 30000 m   30000 m
<result>E</result>
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?