For a monthly subscription fee, a video download site allows people to download and watch up to five movies per month. Based on past download histories, the following table gives the estimated probabilities that a randomly selected subscriber will download 0, 1, 2, 3, 4 or 5 movies in a particular month.

If a subscriber is selected at random, what is the estimated probability that this subscriber downloads 

a. Three or fewer movies?
b. At most three movies?
c. Four or more movies?
d. Zero or one movie?
e. More than one movie?

Number of downloads 0 2 3 45 Estimated probability 003 045 0.25 0.0 0.10 0.07