Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
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 9856 sq. metres.
Answer
Answer (as printed):
Explanation
Clearly, the cow will graze a circular field of area 9856 sq. metres and radius equal to the length of the rope. Let the length of the rope be $R$ metres. $$\text { Then, } \pi R^{2}=9856 \Leftrightarrow R^{2}=\left(9856 \times \frac{7}{22}\right)=3136 \Leftrightarrow R=56 \text {. }$$ ∴ Length of the rope $=56 \mathrm{m}$.