Question

An urn contains seven red and five white balls. Four balls are randomly drawn from the urn in succession with replacement. That is after each drawn the selected ball is returned to the urn. What is the probability that for balls drawn from the urn or white?

Answer 1

Complete Question:

An urn contains seven red and five white balls. Four balls are randomly drawn from the urn in succession with replacement. That is after each drawn the selected ball is returned to the urn. What is the probability that four balls drawn from the urn are white?

Answer:

The probability of drawing four white balls is 0.03014

Explanation:

Given;

7 red balls

5 white balls

total number of balls = 7 + 5 = 12

each time a white ball is drawn, the probability = 5 / 12

The probability of drawing four white balls is given by;

P= P(1st white AND 2nd white AND 3rd white AND 4th white)

P = P(1 st white) x P(2nd white) x P(3rd white) x P(4th white)

P = (5 / 12) x (5 / 12) x (5 / 12) x (5 / 12) (with replacement)

`P = ((5)^4)/((12)^4)\\\\P = (625)/(20736)\\\\P = 0.03014`

Therefore, the probability of drawing four white balls is 0.03014