# Jar Marbles

A jar contains 5 red marbles, numbered 1 to 5, and 12 blue marbles numbered 1 to 12.

a) A marble is chosen at random. If you're told the marble is red, what is the probability that it has the number 3 on it?

b) The first marble is replaced, and another marble is chosen at random. If you're told the marble has the number 1 on it, what is the probability the marble is red?

1. 👍 1
2. 👎 1
3. 👁 1,555
1. a) one of the five red marbles has the number 3 on it, so the probability is 1/5

b) two marbles have the number 1 on them, one red and one blue
... so the probability is 1/2

1. 👍 2
2. 👎 2

## Similar Questions

1. ### math

A bag contains 5 red marbles, 6 white marbles, and 8 blue marbles. You draw 5 marbles out at random, without replacement. What is the probability that all the marbles are red? The probability that all the marbles are red is? What

2. ### Probability

jeff has 8 red marbles, 6 blue marbles, and 4 green marbles that are the same size and shape. he puts the marbles into a bag, mixes the marbles, and randomly picks one marble. what is the probability that the marble will be blue?

3. ### Math

A bag contains 9 red marbles, 8 white marbles, and 6 blue marbles. You draw 4 marbles out at random, without replacement. What is the probability that all the marbles are red? 1 The probability that all the marbles are red is...?

4. ### Statistics

What is the probability of randomly selecting a red marble from a jar that contains 10 red marbles and 20 blue marbles?

1. ### Math ~ Check Answers ~

1. There are 35 marbles in a bag: 9 blue marbles, 8 green marbles, 4 red marbles, 8 white marbles, and 6 yellow marbles. Find P (red). Write the probability as a fraction in simplest form, a decimal, and a percent. a.) 4/31,

2. ### Statistics Probability

A jar contains 5 red marbles, numbered 1 to 5, and 11 blue marbles numbered 1 to 11. a) A marble is chosen at random. If you're told the marble is red, what is the probability that it has the number 2 on it? b)The first marble is

3. ### Stats

Which of the following are binomial experiments? (more than one is possible) 1.) A store finds that 32% of people who enter the store will make a purchase. During a day, 50 people enter the store. The random variable represents

4. ### math

a jar contains 5 blue marbles, 8 red marbles,4 white marbles,and 3 purple marbles. suppose you pick a marble at random not looking. what is the chance of getting a red marble

1. ### Stats

You draw two marbles at random from a jar that has 20 red marbles and 30 black marbles without replacement. What is the probability that both marbles are red?

2. ### Math

The ratio of red marbles to blue marbles in a jar is 2 to 5. If there are 35 blue marbles in the jar, how many red marbles are there? 5 x7 =35 2x7=14 red marbles is this right

3. ### Marbles

A jar contains 9 red marbles numbered 1 to 9 and 7 blue marbles numbered 1 to 7. A marble is drawn at random from the jar. Find the probability that the marble is blue or even-numbered.

4. ### math

The diagram below shows the contents of a jar from which you select marbles at random. There are 4 red marbles, 7 blue marbles, and 5 green marbles. (A). What is the probability of selecting a red marble, replacing it, and then