<span title="Probability......................?">Probability.................</span>

Question

A jar contains 2 blue chips, 3 pink chips, and 4 yellow chips. Jerry choses 2 chips from the jar. He does two experiments or trials with the chips and returns the chips to the bag after each trial.

a) In the first trial, Jerry draws one chip and does not return it to the jar. Then he chooses another chip. Written as a fraction, What is the probability that both chips are blue?

b)In a new trial with the same bag of chips, jerry draws one chip, returns it to the jar, and then draws another chip. What is the probability, written as a fraction, of choosing 2 blue chips in this trial?

Answer 1

a.2/9+1/8=3/17

b.2/9+2/9=4/18=2/9

Answer 2

a.) 3/9 = 1/3

b.)4/9

Answer 3

There are 9 chips in all.  

(a) The probability of a blue chip on the first draw is 2/9; the probability of a blue chip on the second draw given a blue chip on the first draw is 1/8.  So the probability of two blue chips is:

    2/9 * 1/8 = 2 /72 = 1/36

(b) Since the chips are drawn with replacement, the probability of a blue chip on each draw is the same, namely 2/9.  So the probability oof two blue chips is:

  2/9  * 2/9  = 4/81

Answer 4

a:  (2/9) * (1/8) = 2/72=1/36

b:  (2/9) * (2/9) = 4/81