Question

A bag contains 7 red balls and 5 white balls. Two balls are drawn without replacement. (Enter your probabilities as fractions.)

(a) What is the probability that the second ball is white, given that the first ball is red?


(b) What is the probability that the second ball is red, given that the first ball is white?


(c) Answer part (a) if the first ball is replaced before the second is drawn.

Answer 1

Answer:-

Given That:-

A bag contains 7 red balls and 5 white balls. Two balls are drawn without replacement. (Enter your probabilities as fractions.)

Probability is = favorable/total

Total = 7 red + 5 white = 12

(a) What is the probability that the second ball is white, given that the first ball is red?

It is given that first ball is red

So total left would be 6 red + 5 white = 11

P(white) = 5/11= 0.45
(b) What is the probability that the second ball is red, given that the first ball is white?

Here also total = 11

P(red) = 7/11

(c) Answer part (a) if the first ball is replaced before the second is drawn.?

If first ball is replaced then total will be 12

Required probability = 5/12