Probability Review

Vocabulary

100

The chance that something is likely to occur is called...

probability

200

What is the meaning of "!" ?

factorial

300

What is it called when two events happen at once?

Compound Events

400

What is it called when the outcome of the first event affects the outcome of the 2nd event?

Dependent event

500

What is it called when there is an arrangement where order matters?

Permutation

Basic Probability

100

If you draw a card at random from a regular deck of cards what is P(red king)?

2/52 or 1/26

200

In your drawer you have 3 white shirts, 4 blue shirts, and 5 black shirts. Find P(black shirt).

5/12

300

On a spinner with 6 sections numbered 1-6, what is P(4)?

1/6

400

On a regular 6-sided die, what is P(even number)?

3/6=1/2

500

A bag contains: 8 blue marbles, 9 red marbles, 5 green marbles, and 2 yellow marbles. What is P(red or yellow)?

11/24

Counting Principle and Permutations

100

You have 10 pairs of jeans, 5 shirts, and 3 pairs of shoes. How many different outfits can you make using 1 item from each category? (hint: use a tree diagram if needed)

10x5x3=150 outfits

200

You bought 8 new books at the store. How many ways can all 8 be arranged in a row on your bookshelf?

8!=40,320

300

You are taking a photo for the school newspaper. You have 6 models for the photo shoot but can only use 4 for the photo. How many ways can 4 models line up?

6P3=6x5x4x3=360

400

You need to make a new password for your email. You must have 4 letters followed by 1 number(you CAN repeat letters and numbers). How many options do you have for your password?

26x26x26x26x10=4,569,760

500

DAILY DOUBLE! This question is worth 1000 points. A garage code is made up of 6 digits. Which will have more options: a code that can repeat numbers or one that cannot repeat numbers? Explain why.

One that can repeat would be 10x10x10x10x10x10=1,000,000 and one that can't repeat would be 10x9x8x7x6x5=151,200

Compound Events

100

You roll a regular 6-sided die 2 times. What is P(odd number then 2)?

1/2x1/6=1/12

200

You spin a spinner then draw a card from a regular deck of cards. The spinner has 4 sections (blue, purple, pink, yellow). What is P(blue then heart)?

1/4x1/4=1/16

300

A purse contains four $5 bills, five $10 bills, and three $20 bills. Two bills are selected without being replaced. What is the probability that 2 $5 bills will be selected? P($5 then $5)?

4/12x3/11=12/132=1/11

400

You are a grandparent! You already have 6 granddaughters, what is the probability that the next one will be a girl?

1/2

500

You have a bag of candy with 10 snickers, 5 milky way, and 4 twix. What is the probability that you will get 2 snickers in a row if you don't replace the first one?

10/19x9/18=90/342=5/19

Comparing Probabilities (using percents)

100

Gummy worms come in 4 different colors(green, red, yellow, and orange). What is the probability of picking a yellow gummy worm? (answer must be a percent)

25%

200

You have a spinner with 6 sections. 2 sections are red, 1 is purple, and 3 are green. What is the probability of spinning a green? a red? which has a better probability? (hint:use a percent)

50% green vs. 33% red. Green has better probability.

300

Suppose I was making cookies and I burned 8 cookies out of my batch of 40. If I made 100 cookies how many would you predict I would burn?

8/40=?/100. cross multiply. 20 cookies

400

I was stocking the shelf with glass plates. I am a little clumsy and and dropped 7 plates out of 70. If I continue being clumsy, how many plates will I drop out of 300?

What is 7/70=?/300. cross multiply. 30 plates.

500

The milk at the grocery store always has 3 expired gallons out of the 20 on the shelf. What is the percent of expired gallons? If I want the percent to be 20% how many could be expired out of 20?

15% ?/20=.2 , 4 gallons.