Answer:

Therefore, each pupil in the classroom has approximately 4.5 cubic meters of air space available.

Step-by-step explanation:

To calculate the cubic meters of air space available for each pupil in the classroom, you need to find the volume of the classroom and then divide it by the number of pupils.

The volume of a rectangular prism (like a classroom) is calculated by multiplying its length, width, and height. In this case, the length is 9 meters, the width is 7 meters, and the height is 3 meters.

Volume = length × width × height

Volume = 9m × 7m × 3m

Volume = 189 cubic meters

So, the total volume of the classroom is 189 cubic meters.

To find the cubic meters of air space per pupil, divide the total volume of the classroom by the number of pupils.

Air space per pupil = Total volume of classroom / Number of pupils

Air space per pupil = 189 cubic meters / 42 pupils

Air space per pupil ≈ 4.5 cubic meters