Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
Area of a rectangle is 150 metre sq. When the breadth of the same rectangle is increased by 2 meter and the length decreased by 5 metre the area of the rectangle decreases by 30 metre square. What is the perimeter of the square whose side are equal to the length of the rectangle? [RBI Officers Gr. 'B' (Phase I) Exam, 2015]
(a)76 m
(b)72 m
(c)120 m
(d)60 m
Answer
Answer (as printed): D
Explanation
Let the length of rectangle be $l \mathrm{m}$ And the breadth of the rectangle be $b$ m Then area of the rectangle $=l \times b$ $$l b=150 \mathrm{m}^{2}$$ According to the question. $$\begin{aligned} & (l-5) \times(b+2)=150-30=120 \\ & (l-5) \times(b+2)=120 \end{aligned}$$ On solving both equations we get, $l=15 \mathrm{m}$ and $b=10 \mathrm{m}$ side of square = length of rectangle (given) So, the perimeter of the square $=4 \times l=4 \times 15=60 \mathrm{m}$