An urn contains 6 white balls, 4 black balls, 5 red balls and 5 green balls
MATHEMATICS · Multi-part · A Level · Mathematics · Probability · Probability
Problem
An urn contains 6 white balls, 4 black balls, 5 red balls and 5 green balls. One ball is drawn at random. Consider the following events:
W: the ball drawn is white,
B: the ball drawn is black,
R: the ball drawn is red.
Answer the questions below:
(i) Show that the events W, B and R are pairwise mutually exclusive.
(ii) Calculate the probability that the ball drawn is white, black or red.
(iii) Verify that the value obtained in part (ii) equals the sum of the individual probabilities P(W), P(B) and P(R).