Subject: General Aptitude · Chapter: Area · Exam: 2006 · Marks: · Difficulty:
The circumference of a circular ground is 88 metres. A strip of land, 3 metres wide, inside and along the circumference of the ground is to be levelled. What is the budgeted expenditure if the levelling costs ₹ 7 per square metre?
(a)₹ 1050
(b)₹ 1125
(c)₹ 1325
(d)₹ 1650
Answer
Answer (as printed): D
Explanation
Let the radius of the ground be $R$ metres. Then, $2 \pi R=88 \Rightarrow R=\left(\frac{88 \times 7}{2 \times 22}\right)=14 \mathrm{m}$. $$\begin{aligned} & \text { Area of land strip }=\pi\left[(14)^{2}-(11)^{2}\right] \mathrm{m}^{2}=\left(\frac{22}{7} \times 25 \times 3\right) \mathrm{m}^{2} \\ & \quad=\left(\frac{1650}{7}\right) \mathrm{m}^{2} . \\ & \therefore \quad \text { Cost of levelling }=₹\left(\frac{1650}{7} \times 7\right)=₹ 1650 . \end{aligned}$$