Hey! Thanks for submitting your question to Brainly!
If we know that the machine fills 8 per minute, we can multiply 8*60 (minutes in an hour) = 480
Now, we know that the machine fills 480 cans per hour. We need to find how many cans it fills in 8 hours so we'll multiply 480*8 and get your answer of 3840.
I'm glad I could help but next time try using a calculator :).