SSC CPO 2020 PYQ — Question 131

The correct answer is option 3 i.e. 85,320.

Here ABCD is the rectangle

Breadth of the rectangle AD = 12 m

Length of the rectangle AB = 2 × 12 = 24 m

Breadth is the diameter of the small semicircle, so radius r₁ = 12/2 = 6 m

Length is the diameter of the big semicircle, so radius r₂ = 24/2 = 12 m

The area of the lawn = area of the rectangle + area of the two small semi circle + area of the big semi circle.

= l × b + 2 × ($\dfrac{\pi}{2}$r₁²) +  2 × ($\dfrac{\pi}{2}$r₂²)

= 12 × 24 + 22/7 × 36 + 22/7 × 144

= 288 + 565.20

= 853. 20 m²

The total cost of levelling the entire lawn at the rate of Rs 100 per square metre = 853.20 × 100 = Rs. 85320