Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
A park square in shape has a 3 metre wide road inside it running along its sides. The area occupied by the road is 1764 square metres. What is the perimeter along the outer edge of the road?
(a)576 metres
(b)600 metres
(c)640 metres
(d)Data inadequate
(e)None of these
Answer
Answer (as printed): B
Explanation
Let the length of the outer edge be $x$ metres. Then, length of the inner edge $=(x-6) \mathrm{m}$. $$\begin{aligned} & \therefore x^{2}-(x-6)^{2}=1764 \Leftrightarrow x^{2}-\left(x^{2}-12 x+36\right)=1764 \\ & \Leftrightarrow 12 x=1800 \Leftrightarrow x=150 . \\ & \therefore \text { Required perimeter }=(4 x) \mathrm{m}=(4 \times 150) \mathrm{m}=600 \mathrm{m} . \end{aligned}$$