Question

Assume that two marbles are drawn without replacement from a box with 1 blue, 3 white, 2 green, and 2 red marbles.

Find the probability of the indicated result.
Both marbles are red.
A. 1/16
B. 3/56
C. 1/28
D. 1/4

Answer 1

C. 1/28

Explanation:

Assume that two marbles are drawn without replacement from a box with 1 blue, 3 white, 2 green, and 2 red marbles.

We have a total of 8 marbles

1st draw:

P(red) = number of red/total = 2/8 = 1/4

We now have 1 blue, 3 white, 2 green, and 1 red marbles for 7 marbles

2nd draw:

P(red) = number of red/total = 1/7

Multiply the probabilities together

P(red,red) = 1/4 * 1/7 = 1/28