Question

A bag contains 7 red marbles, 3 blue marbles and 2 green. If two marbles are drawn out of the bag, what is the probability, to the nearest 1000th, that both marbles drawn will be blue?

Answer 1

Answer:

0.0455

Step-by-step explanation:

The formula for calculator probability is

# of favorable outcomes / # of possible outcomes

The total number of marbles in the bag:

7+3+2=12

Probability of the first marble being blue:

3/12

Probability of the second marble being blue:

2/11 -- 2 because only 2 blue marbles left after drawing the first one out, 11 because after taking the first marble out, we have 11 marbles left in the bag

Formula for both events happening:

p(A and B) = p(A) * p(B)

In this problem,

A = first one blue

B = second one blue

Probability that if two marbles are drawn out of the bag, both are blue:

3/12 x 2/11 = 0.045454

Rounded answer:

0.0455 (or 4.55%)