In order to calculate the volume of a cylinder, we can use the following formula:

Where r is the base radius and h is the height.
If the circumference is 8, we have:

Now, calculating the volume, we have:

So the correct option is the second one.
She gets to the library at 5:30. Half an hour is equal to 30 minutes, and if she leaves at 5:00, she will be there in thirty minutes.
200+50+4 I think is the answer