Question

A bag has 6 red rocks, 1 orange rock, 4 blue rocks, 1 white rock, and 7 yellow rocks. You randomly pull a rock from the bag, keep it out and then pull out another one. What is the probability of not getting a orange and then not getting a orange?

Answer 1

Answer: 17/19

Explanation:

Number of red rocks = 6

Number of orange rock = 1

Number of blue rocks = 4

Number of white rock = 1

Number of yellow rocks = 7

Total number of rocks = 19

Probability of not getting a orange the first time will be (1 - 1/19) = 18/19.

Probability of not getting an orange the second time will be: (1 - 1/18) = 17/18

Probability of not getting an orange on both occasion will be:

= 18/19 × 17/18

= 17/19