It is not true that CO2 is released during photosynthesis, rather its the opposite. Carbon dioxide is a raw material for the production of starches and cellulose through photosynthesis. Atmospheric carbon dioxide is captured during the light dependent reactions of photosynthesis then used for the production of starch, glucose and cellulose in the light independent reactions (Calvin cycle) of photosynthesis.
In aerobic cellular respiration, oxygen rather than Carbon dioxide is a requirement because it is needed as the terminal electron acceptor in the production of ATP.
This problem is just a normal math equation. You divide the price by how much space you are covering to get the smallest ratio(15 million divided by 1.8 million). After dividing you get the answer of $8.33 per cubic yard.
