An urn contains 4 blue balls, 5 yellow balls and 7 red balls. if a single ball is selected, find the probability thet the ball is

Red?
Not blue?
blue or yellow

1 answer

a) 7/16 red.

b) 5/16 + 7/16= 12/16=>3/4

c) 4/16 + 5/16 = 9/16