Guests = 320 portions of beets served = 8 oz. size of beet can = 40 oz. how many cans of beets required?

Assuming each guest isn't a fatty and every guest eats only 1 portion

320 times 8oz=2560 oz needed

number of cans needed times oz per can=oz we need

n times 40=2560

divide both sides by 40

n=64

64 cans needed