Subject: General Aptitude · Chapter: Area · Exam: 2007 · Marks: · Difficulty:
The area of a grassy plot is 480 sq. m. If each side had been 5 m longer, the area would have been increased by 245 sq. m. Find the length of the fence to surround it.
(a)87 m
(b)88 m
(c)90 m
(d)None of these
Answer
Answer (as printed): B
Explanation
Let the length and breadth of the plot be $l$ and $b$ metres respectively. Then, $l b=480$ And, $(l+5)(b+5)=725 \Rightarrow l b+5(l+b)+25=725$ $$\Rightarrow 5(l+b)+505=725 \Rightarrow(l+b)=\frac{220}{5}=44 .[\because l b=480]$$ ∴ Length of the fence $=2(l+b)=(2 \times 44) \mathrm{m}=88 \mathrm{m}$.