Conditional Probability

  8.  A bag contains 5 red marbles and 4 pink marbles. A marble is randomly drawn and then replaced. What is the probability the first marble is pink and the second is red?

• 26.9%
• 24.7%
• 20.0%
• 5%

 9.  A bag contains 5 red marbles and 4 pink marbles. A marble is randomly drawn and does not get replaced. What is the probability that both marbles are red?

• 27.8%
• 24.7%
• 20.0%
• 4%

10.  A bag contains 5 red marbles and 4 pink marbles. Joe randomly draws a marble and then puts it back. Then he draws a pink marble twice?

• 27.8%
• 24.7%
• 16.7%
• 19.8%

11. A coin is flipped and a die is rolled. What is the probability that the coin lands heads up and the number rolled is 1?

• 6.3%
• 25.0%
• 8.3%
• 2.8%

  12.  A day in the year is randomly chosen. Given the day is in the month of December, what is the probability the day is the 25^th? (December has 31 total days.)

• 8.5%
• 8.84%
• 80.6%
• 3.2%

13.  Jorge has a collection of pictures he took at the zoo. He likes to use his pictures as backgrounds for his laptop. Jorge has the slideshow setting on his laptop, which causes his background picture to automatically change every five minutes. Out of Jorge’s collection of pictures, a forth of them are of sea lions, a third of them are of elephants, half of them are of bears, and 20 of them are of gorillas. What is the probability that the laptop will display a picture of a sea lion followed by a picture of a bear as a decimal? Round your answer to the nearest hundredth.    

• .13
• .08
• .001
• .17

14. Amber rolls two dice and it is known that the sum of the numbers is 7. What is the
  probability one die is a 5?

• 16.7%
• 19.8%
• 33.3%
• 8.3%

15.  A box contains 7 yellow pencils and 3 black pencils. Michael randomly chooses a pencil and does not replace it. Then he chooses a second pencil. What is the probability both pencils are yellow?

• 54.4%
• 46.7%
• 49.0%
• 23.3%

16.  A box contains 7 yellow pencils and 3 black pencils. Michael randomly chooses a pencil and does not replace it. Then he chooses a second pencil. What is the probability the first pencil is yellow and the second pencil is black?

• 54.4%
• 46.7%
• 49.0%
• 23.3%

17.  A box contains 7 yellow pencils and 3 black pencils. Michael randomly chooses a pencil and replaces it. Then he chooses a second pencil. What is the probability that both pencils are yellow?

• 21.0%
• 46.7%
• 49.0%
• 23.3%