A circular lawn of 98 meters is surrounded by a path of 14 meters wide. What is the area of the path in meters2?
The Usual Method:
The two edges of the path makes concentric circles, one with a radius of 98 meters and another with a radius of 98 + 14 = 112 meters.
Hence area of path =
= 44 x 210 = 9240 meters2
Estimated Time to arrive at the answer = 45 seconds.
Observe that both 98 and 14 are multiples of 7 and when multiplied by , will have in the numerator a number which is a multiple of 11 ( 22 is in the numerator of the value of ). Only option ‘3’ is a multiple of 11 and hence it is the answer.
Estimated Time to arrive at the answer = 5 seconds.