A rectangular lawn whose length is twice of its breadth is extended by having four semicircular portions on its sides. What is the total cost (in Rs.) of levelling the entire lawn at the rate of Rs. 100 per square metre, it the smaller side of the rectangular lawn is 12 m? (Take π = 3.14)

A. 85,320

B. 78,650

C. 86,540

D. 97,625

Answer: Option A

Solution (By Examveda Team)

Breadth = 12 m
Length = 24 m
Cost = 100 Rs./m²
r = 6
R = 12

π × 144 + π × 36 + 288
= 3.14 × 144 + 3.14 × 36 + 288
= 853.2
∴ Total cost = 853.2 × 100 = Rs. 85320