Question

An urn contains 9 black and 8 pink balls. Five balls are randomly drawn from the urn in succession, with replacement. That is, after each draw, the selected ball is returned to the urn. What is the probability that all 5 balls drawn from the urn are black

Answer 1

0.0416

Explanation:

Given :

Number of balls :

Pink = 8 ; black = 9

Total number of balls = 8+9 = 17

Choosing with replacement :

Probability = required outcome / Total possible outcomes

Required outcome = number of black balls

Total possible outcomes = total number of balls

P(black) = 9/17

Number of picks = 5

Hence, Probability that all 5 picks are black :

P(all black) = 9/17 * 9/17 * 9/17 * 9/17 * 9/17 = 0.0415879

= 0.0416