A bag of marbles contains six red marbles, four blue marbles, eight green marbles, and two yellow marbles. A marble is selected at random from the bag and.....

Question

not replaced, and then another marble is selected.

 

What is the probability that the first marble selected in the situation described is red and the second is blue?

 

Answer 1

The two selections are independent, the balls in the bag do not know what was drawn the first time.

 

20 marbles are in the bag, six of them are red. The probability of picking a red is 6/20.

 

20 marbles are in the bag, four of them are blue. The probability of picking a blue one is 4/20.

 

To find the probability of two independent events, multiply the probabilities of each event.

 

Probability of picking a red, then a blue is (6/20)(4/20), or 3/50.