Train a pull into the sation every 6 hours . The train B pulls into the sation every 3 hours . They both pulled thr sation at 3pm. When is the next time they with both pull into the sation at the same time?

9 pm

Explanation:

A pulls into the station every 6 hours while B pulls into the station every 3 hours. Hence, for every time A pulls up, B must have pulled up twice.

They both pulled into the station at 3 pm. At 6 pm (3 pm + 3 hours), B would pull into the station while A would still be on the road. At 9 pm (3 pm + 6 hours), B will pull in once more while A will just be pulling up the first time since 3 pm.

Hence, the next time both trains will pull into the station at the same time would be 9 pm.

a. the production of carbon dioxide through the process of photosynthesis

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.