Question:
The dimensions of a cinema hall are 100 m, 50 m and 18 m. How many persons can sit in the hall, if each person requires 150 m3 of air?
Solution:
The dimensions of a cinema hall are $100 \mathrm{~m} \times 50 \mathrm{~m} \times 18 \mathrm{~m}$.
i.e., volume of air in the cinema hall $=100 \times 50 \times 18=90000 \mathrm{~m}^{3}$
It is given that each person requires $150 \mathrm{~m}^{3}$ of air.
$\therefore$ The number of persons that can sit in the cinema hall $=\frac{\text { volume of air in hall }}{\text { volume of air required by } 1 \text { person }}=\frac{90000}{150}=600$