Posted by Andrea on .
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

statistics 
Makhasane,
a) 7/16 red.
b) 5/16 + 7/16= 12/16=>3/4
c) 4/16 + 5/16 = 9/16