A 4 m telescope can collect a given amount of light in 3 hour. Under the same observing conditions, how much time would be required for a 8 m telescope to perform the same task?

The light collection of a telescope is proportional to the AREA of the objective lens or mirror. So the 8m collects 4 times as much light as the 4m does in the same time. Or the bigger one collects the same amount of light in 1/4 of the time that it takes the smaller one.
Under the same observing conditions that the 4m needs 3 hours, the 8m monster can do the job in 45 minutes.

Iread this book last year so take this with a grain of salt.gene jumps from the tree to compete with finny due to the fact that gene is always trying to do better than finny. he is put under the grasp of peer pressure due to finny almost forcing him to do this. ever since he first jumped finny kept pressuring him to jump since he thought gene enjoyed jumping.rather than uses this answer you should probably just reread chapters 3-4