Study the information carefully to answer the following questions:
A bucket contains 8 red, 3 blue and 5 green marbles.
If 3 marbles are drawn at random, what is the probability that none is red ?
Number of ways of drawing 3 marbles out of 16
$$n(S) = C^{16}_3 = \frac{16 \times 15 \times 14}{1 \times 2 \times 3}$$
= $$560$$
Out of the three drawn marbles, none is red, i.e., they will be either blue or green.
=> $$n(E) = C^8_3 = \frac{8 \times 7 \times 6}{1 \times 2 \times 3}$$
= $$56$$
$$\therefore$$ Required probability = $$\frac{n(E)}{n(S)}$$
= $$\frac{56}{560} = \frac{1}{10}$$
Create a FREE account and get:
Day-wise Structured & Planned Preparation Guide
By proceeding you agree to create your account
Free CAT Schedule PDF will be sent to your email address soon !!!
