Question

a rectangular ground is 90 M long and 32 M broad in the middle of the ground there is a circular track of radius 40 m find the cost of surfing the remaining portion @ 50 rupees per square metre

Answer 1

first we find area of rectangular ground
area of rectangle= length× breath
= 90 ×32
=2880sq.m
Then we find area of circular track
$area \: of \: circle = \pi \: r {}^{2}$
=3.14× 1600
= 5024sq.m
remaining portion =5024-2880
= 2144sq.m
cost of remaining portion @50 rupees per sq.m = 2144×50=107200 rupees