Subject: General Aptitude · Chapter: Area · Exam: 2007 · Marks: · Difficulty:
The area of a playground is 15400 square metres. What is its perimeter? I. It is a circular playground. II. It costs ` 30800 to clean the playground @ ` 2 per sq. ft.
Answer
SELF-PRACTICE — the source book printed no answer.
Nothing is invented here, so this question has no answer on record.
Explanation
I. Since the playground is circular, we have : $$\begin{aligned} & \pi r^{2}=15400 \Rightarrow r^{2}=\frac{15400 \times 7}{22}=4900 \Rightarrow r=70 \mathrm{m} \\ & \Rightarrow \text { Perimeter }=2 \pi r=\left(2 \times \frac{22}{7} \times 70\right) \mathrm{m}=440 \mathrm{m} . \\ & \text { II. Area }=\left(\frac{30800}{2}\right) \mathrm{m}^{2}=15400 \mathrm{m}^{2} . \end{aligned}$$