Question

A bag contains exactly three red marbles, five yellow marbles and two blue marbles. If three marbles are drawn from the bag without replacement, what is the probability that all three will be the same color? Express your answer as a common fraction

Answer 1

• 11/120

Explanation:

• Red = 3
• Yellow = 5
• Blue = 2

Possible options would be red or yellow as only two blue marbles.

Probability of 3 red:

• 3/10*2/9*1/8 = 1/120

Probability of 3 yellow:

• 5/10*4/9*3/8 = 1/12

Probability of same three is:

• 1/120 + 1/12 = 11/120