A bag contains 10 red 6 blue and 4 green poker chips You ran

A bag contains 10 red, 6 blue, and 4 green poker chips. You randomly select two chips without replacement. First, use a tree diagram to map out the sample space:

a. What is the probability the second chip is green?

b. What is the probability you get no blue chips?

Solution

TOTAL WE HAVE 20 CHIPS

10 RED 6 BLUE AND 4 GREEN

A) PROBABILITY THAT SECOND CHIP IS GREEN

CASE 1) WHEN 1ST CHIP IS NOT GREEN

THEN THE PROBABILITY OF GETTING A GREEN CHIP IS 4/19

CASE 2 WHEN THE 1ST CHIP WAS GREEN

THEN THE PROBABILITY WILL BE 3/19

WE USE 19 BECAUSE THIS IS SECOND ATTEMPT AND THE TOTAL CHIP WILL REDUCE BY 1

B) PROBABILITY OF GETTING BLUE CHIP = 6/20 = 3/10

PROBABILITY OF NOT GETTING BLUE CHIP = 1 - 3/10 = 7/10

HENCE THE PROBABILITY WE GET NO BLUE CHIP AMONG 2

= 2C0(3/10)^0*(7/10)^2 = 49/100 = 0.49