A jar contains 5 blue marbles, 8 red marbles, 4 white marbles, and 3 purple marble suppose you pick one at random. Find the probability of drawing a red, then white marble, if the 1st one is but back.

Tutors, sign in to answer this question.

Lauren H. | Middle & High School MathMiddle & High School Math

First let's find the probability of drawing a red marble. I know that the probability is my (# of red marbles)/(total # of marbles) so 8/20 which we can simplify to 2/5.

Since the first marble is put back, I know that I will still have 20 total marbles. Therefore the probability of drawing a white marble is (# of white marbles)/20 which is 4/20. We can simplify this to 1/5.

The probability of drawing a red marble and then a white marble is going to be the product of these probabilities.

Therefore the total probability is the probability of the first even occurring times the probability of the second event occurring.

(probability of red)*(probability of white) = total probability

(2/5)*(1/5)=2/25

So we can expect to draw a red marble then a white marble 2 out of 25 times that we perform this experiment.

Hope this helps!

Already have an account? Log in

By signing up, I agree to Wyzant’s terms of use and privacy policy.

Or

To present the tutors that are the best fit for you, we’ll need your ZIP code.

Your Facebook email address is associated with a Wyzant tutor account. Please use a different email address to create a new student account.

Good news! It looks like you already have an account registered with the email address **you provided**.

It looks like this is your first time here. Welcome!

To present the tutors that are the best fit for you, we’ll need your ZIP code.

Please try again, our system had a problem processing your request.

Stephanie O.

Ivy Grad - Flexible, Friendly, Gets Results (10+ Years Experience)

$13.75 per 15 min

View Profile >

Gary M.

Experienced, patient math tutor who can help YOU!

$10 per 15 min

View Profile >

Michael B.

Effective Tutor Specializing in Mathematics

$10 per 15 min

View Profile >