Question

There are 15 marbles in a bag. Two marbles are white, five are blue, and eight are red. You pick two marbles out of the bag, without putting the first one back. Find the probability of two blues in a row. (Please and thank you!)

Answer 1

Answer: 2/21

Step-by-step explanation:

Number of white marbles = 2

Number of blue marbles = 5

Number of red marbles = 8

Total number of marbles = 15

The probability of picking the first blue marble will be 5/15 = 1/3

When the first marble is picked, there'll be 4 blue marbles and 14 total marbles left, then the probability of picking another blue marble will be 4/14 = 2/7.

Therefore, the probability of two blues in a row will be:

= 1/3 × 2/7

= 2/21