Probability Review

Dice

100

When rolling 1 die.  P(even number) = ?

1/2

200

When rolling 2 dice.  P(7) = ?

1/6

300

When rolling 2 dice, P(7 or greater) = ?

7/12

400

You roll a red die and yellow die.  The value of the red die is a, and the value of the yellow die is b.  What is the probability 3a + b = 10?

1/18

500

When rolling 1 die, there are 6 outcomes.  When rolling 2 dice, there are 36 outcomes.  How many outcomes are there if you roll 3 dice?

216

Balls

100

In a bag, there are 3 red balls, 4 yellow balls, and 5 blue balls.  You pick one ball.  P(yellow) = ?

1/3

200

In a bag, there are 3 red balls, 4 yellow balls, and 5 blue balls.  You pick one ball.  P(red or blue) = ?

2/3

300

In a bag, there are 3 black balls and 2 red balls.  You take two at the same time.  P(both black) = ?

3/10

400

In a bag, there are 3 black balls and 2 red balls.  You take two at the same time.  P(red and black) = ?

3/5

500

In a bag, there are 3 black balls and 2 red balls.  You take one, put it back in, then take another one.  P(both black) = ?

9/25

Cards

100

There are 10 cards, numbered 1 to 10.  You pick one card.  P(multiple of 4) = ?

1/5

200

There are 4 cards, numbered 1 to 4.  You draw 2 cards simultaneously (=at the same time).  P(both are odd) = ?

1/6

300

There are 4 cards, numbered 1 to 4.  You draw 2 cards simultaneously (=at the same time).  P(sum is 4 or greater) = ?

5/6

400

There are 5 cards, numbered 1 to 5.  You draw 2 cards simultaneously (=at the same time).  P(product is odd) = ?

3/10

500

There are 5 cards, numbered 1 to 5.  You draw one card, return it, then draw another.  P(you draw the same number) = ?

1/5

Coins

100

You flip a coin 2 times.  P(2 heads) = ?

1/4

200

You flip a coin 2 times.  P(heads and tails) = ?

1/2

300

You flip a coin 3 times.  P(3 heads) = ?

1/8

400

You flip a coin 2 times.  P(at least 1 heads) = ?

7/8

500

You flip a coin 8 times.  How many total outcomes are there?

256

Perms/Combs

100

How many ways can you arrange 3 books on a bookshelf?

6 ways

200

There are 4 ice cream flavors.  You can order 2 flavors.  How many 2-flavor combinations are there?

6 combinations

300

How many ways can you choose 3 items out of 6 (A, B, C, D, E, and F) and arrange them in sequence?

120 ways

400

There are 4 boys and 3 girls.  2 are randomly chosen to be class representatives.  How many 2-student combinations are there?

21

500

There are 12 horses in a race.  How many ways can 1st, 2nd, and 3rd place occur?

1320 ways