You forgot the options, but I can still help you.
What you know is that noone varies more than 8 minutes, I understand it to mean that noone takes more than 8 minutes less or more.
8 minutes more is 45+8=53
8 minutes less is 45-8=37
So the worker's time will be between 37 and 53, including those two numbers:
37≤t≥53
