Probability

Question

A bag contains 100 solid colored balls, of which 20 are red and the rest are either green or yellow. If one ball is to be selected at random from the bag, the probability of the ball selected will be green is 7/20. How many yellow balls are in the bag?

Answer 1

color count

red      20

yellow  80-x

green   x

TOTAL   100

 

P(GREEN) = x/100 = 7/20

Therefore x = 35.