Pre-Algebra Probability Review

Ricardo has the spinner pictured here and a bag of marbles filled with 2 red marbles, 3 green marbles, and 3 blue marbles. What is the probability that Ricardo spins red on the spinner and picks a red marble out of the bag?

• 1 ⁄ 16

• 1 ⁄ 2

• 1 ⁄ 4

• 1 ⁄ 8

If you pick a red marble and keep it, how does that change the probability of getting a green marble when you pick a second time?

• No change

• More likely

• Less likely

• Impossible

A bag contains 3 red marbles, 4 blue marbles, and 5 yellow marbles. You select a marble from the bag and without replacing it select another marble from the bag. What is the probability that you will draw 2 blue marbles?

On Roberto's shelf are 6 mystery books, 5 science books, 4 history books, and 3 adventure books. Roberto will randomly choose 1 book to read and then without replacement will choose another book. What is the probability he will choose an adventure book and then a mystery book?

A bag contains 3 red tiles, 6 green tiles, and 3 blue tiles. A tile will be randomly selected from the bag and then without replacement another tile will be selected. What is the probability that a red tile will be drawn and then a green tile?

Rob and Mary are planning trips to 9 countries this year.  There are 13 countries they would like to visit.  They are deciding which countries to skip.

• combination

• permutation

• neither

Out of 10 balloons, two are small, five are medium, and three are large. Find the odds against a large balloons.

• 3:7

• 3:10

• 7:10

• 7:3

The letters that form the word ALGEBRA are placed in a bowl. What is the probability of choosing a letter other than “A”?

• 2/7

• 5/49

• 5/7

• 10/49

What are the odds in favor of randomly selecting a dime from a dish containing 11 pennies, 6 nickels, 5 dimes, and 3 quarters? 

• 4:1

• 1:4

• 1:5

• 5:1

An impossible event has a probability of _____?

• 1
• 0
• 1/2
• 100