Find the length of a rope by which a cow must be tethered in order that it may be able to graze an area of 154 sq m.

• A. 13 m
• B. 7 m
• C. 12 m
• D. 8 m

Answer: (B)

Length of to the rope = Radius of circle According to the question,?r2 = 154 ? r2 = 154 x (7/22) = 7 x 7 = 49 ? r = ?49 = 7 m