Probability Review

There are 10 boys and 12 girls in a class.  If one student is selected at random from the class, what is the probability it is a girl?

• 1/2
• 1/22
• 6/11
• 6/5

David just got a new credit card in the mail.  What is the probability the second digit of the credit card number is a 3?

• 1/3
• 1/10
• 2/3
• 1/5

Brenda has 18 fish in an aquarium.  The fish are the following colors: 5 orange, 7 blue, 2 black, and 4 green.  Brenda also has a trouble-making cat that has grabbed a fish.  What is the probability the cat grabbed a green fish if all fish are equally capable of avoiding the cat?

• 2/9
• 1/18
• 2/7
• 1/4

You have a cube with each face numbered 1, 2, 3, 4, 5, or 6.  What is the probability if you roll the cube 4 times, you will get the number 5 each time?

• 4/1296
• 4/5
• 1/256
• 1/1296

In a game using two numbered cubes, what is the probability of not rolling the same number on both cubes three times in a row?

• 125/256
• 125/216
• 27/64
• 16/27

Ben has a bag of 40 red triangles and 40 blue triangles.  Without replacement, what is the probability of Ben choosing 2 red triangles?

• .20
• .25
• .30
• .35

Kyle has 4 different kinds of Halloween candy in a bag.  He has 5 chocolate rolls, 6 lollipops, 4 chocolate bars, and 7 peanut butter candies.  What kind of candy must Kyle have picked out of the bag if the probability of picking that kind is 2/11?

• chocolate roll
• lollipop
• chocolate bar
• peanut butter

There are 7 sections of equal size on a spinner.  One is labeled purple.  Two are labeled green, and three are labeled orange.  One section is unlabeled.  What color must be unlabeled section be if the probability of spinning that color is 4/7?

• purple
• green
• orange
• brown

In Florida, 94% of people have a TV.  71% have a TV and a VCR.  What percent of people have a VCR if they already had a TV?

• 66%
• 70%
• 83%
• 76%

If there are ten blocks in a bucket, 7 are red and 3 are yellow, what are the odds of choosing 2 red blocks ( without replacement)?

• 8/15
• 7/30
• 6/15
• 7/15