Rob notices that 55 percent of the people leaving the supermarket chhose plastic bags instead of paper bags. out of 600 people, how many can rob predict will carry plastic bags?

To solve this answer, you are trying to find 55% of 600, because that is the number of people who chose plastic bag.

55% can be re-written as 55/100 OR 0.55 since percentages are always out of 100.

So, we do 0.55*600, which gives us 330. 330 people carry plastic bags.