When concentrations of formaldehyde in the air exceed 33 mu g divided by ft cubed μg/ft3 left parenthesis 1 mu g equals 1 microgram equals 10 superscript negative 6 baseline gram right parenthesis comma 1 μg=1 microgram=10−6 gram, a strong odor and irritation to the eyes often occurs. one square foot of hardwood plywood paneling can emit 3365 mu g μg of formaldehyde per day. a 5 ft by 6 ft sheet of paneling is attached to a wall in a room having floor dimensions of 10 ft by 10 ft and height of 6ft?

Let me reiterate the given. The limit of the concentration of the formaldehyde is 33 μg/ft³. This should be our basis. Now, it is given that each square foot of wood paneling emits 3,365 μg of formaldehyde. Since the wood paneling has dimensions of 5 ft by 6 ft, the area is equal to 30 ft². Therefore, the emitted amount of formaldehyde is:

Emitted formaldehyde = (3,365 μg/ft²)(30 ft²) = 100,950 μg

Next, we determine the volume of the room.
V = 10 ft × 10 ft × 6 ft = 600 ft³

Let's compare the ratio to our basis:
Ratio = 100,950 μg/600 ft³ = 168.25 μg/ft³

Since the limit is just 33 μg/ft³, it exceeded the given limit. Thus, with this condition, there would be strong odor and irritation of the eyes.

The answer is A.
What it is basically saying is 
Cost = 16 times the number of hours minus 10.

Which is exactly what it's asking you to do