Question

A bag has 2 green marbles and 10 brown marbles. Half of the brown marbles are made of glass. A marble is selected at random from the bag. What is the

probability that it is a brown, glass marble?

Answer 1

The sample space is 12. This is because there are 2 green and 10 brown, so 2+10 =12.

Half of the 10 brown marbles are glass, so that would be:

1/2 * 10 = 5 brown, glass marbles.

The probability of picking a brown, glass marble is therefore no of brown, glass marbles/ sample space.

5/12

Answer 2

• 5/12

Explanation:

Total number of marbles:

• 2 + 10 = 12

Number of brown marbles made of glass:

• 10/2 = 5

Required probability:

• P = 5/12