A classroom is 10 m long, 6.4 m wide and 5 m high. If each student be given 1.6 m2 of the floor area,

Length of the classroom = 10 m
Breadth of the classroom = 6.4 m
Height of the classroom = 5 m

Area of the floor $=$ length $\times$ breadth $=10 \times 6.4 \mathrm{~m}^{2}$

No. of students $=\frac{\text { area of the floor }}{\text { area given to one student on the floor }}$

$=\frac{10 \times 6.4}{1.6}$

$=\frac{640}{16}=40$ students

Now, volume of the classroom $=10 \times 6.4 \times 5 \mathrm{~m}^{3}$

$\therefore$ Air required by each student $=\frac{\text { volume of the room }}{\text { number of students }}$

$=\frac{10 \times 6.4 \times 5}{40} \mathrm{~m}^{3}$

$=8 \mathrm{~m}^{3}$