Question

In a bag of 10 marbles, there are 4 blue, 3 red, 2 green, and 1 yellow. What is the probability that you draw one marble that is blue, replace it, and draw another marble that is green? Enter your answer as a fraction in lowest terms. Do not add spaces to your answer. (EX: 1/2)

Answer 1

Answer: 2/25

Work Shown:

A = the 1st marble is blue

B = the 2nd marble is green

Replacement is applied. This makes A and B independent.

P(A) = (4 blue)/(10 total) = 4/10 = 2/5

P(B) = (2 green)/(10 total) = 2/10 = 1/5

P(A and B) = P(A)*P(B) ... see note below

P(A and B) = (2/5)*(1/5)

P(A and B) = 2/25

Note: The equation is valid because events A and B are independent.