Subject: General Aptitude · Chapter: Area · Exam: 2007 · Marks: · Difficulty:
The area of the four walls of a room is $120 \mathrm{m}^{2}$ and the length is twice the breadth. If the height of the room is 4 m, then the area of the floor is
(a)$48 \mathrm{m}^{2}$
(b)$49 \mathrm{m}^{2}$
(c)$50 \mathrm{m}^{2}$
(d)$52 \mathrm{m}^{2}$
Answer
Answer (as printed): C
Explanation
Let breadth $=x$ metres and length $=(2 x)$ metres. Area of 4 walls $=[2(2 x+x) \times 4] \mathrm{m}^{2}=(24 x) \mathrm{m}^{2}$. $$\therefore \quad 24 x=120 \Rightarrow x=5 .$$ So, length $=10 \mathrm{m}$, breadth $=5 \mathrm{m}$. Area of the floor $=(10 \times 5) \mathrm{m}^{2}=50 \mathrm{m}^{2}$.