Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: 2010 · Marks: · Difficulty:
A school room is to be built to accommodate 70 children so as to allow $2.2 \mathrm{m}^{2}$ of floor and $11 \mathrm{m}^{3}$ of space for each child. If the room be 14 metres long, what must be its breadth and height?
(a)11 m, 4 m
(b)11 m, 5 m
(c)12 m, 5.5 m
(d)13 m, 6 m
Answer
Answer (as printed): B
Explanation
Let the breadth and height of the room be $b$ and $h$ metres respectively. Then, area of the floor $=(14 b) \mathrm{m}^{2}$. $$\therefore 14 b=2.2 \times 70 \Rightarrow b=\frac{2.2 \times 70}{14}=11 .$$ Volume of the room $=(14 \times 11 \times h) \mathrm{m}^{3}=(154 h) \mathrm{m}^{3}$. $$\therefore 154 h=11 \times 70 \Rightarrow h=\frac{11 \times 70}{154}=5 .$$
Explanation as extracted from the printed page; notation may be imperfect.