Probability Tic-Tac-Toe

Using the letters M, A, T, and H only once, how many 3-letter combinations are there? (regardless of order)

• 12

• 8

• 4

• 24

Answer explanation

Remember order doesn't matter!

We could have....

*M,A,T

*M,T,H

*A,T,H

*M,A,H

On any given day, the cafeteria serves 3 main dishes (pizza, hamburger, or special) and 3 drinks (white milk, chocolate milk, or apple juice). How many possible choices are there for lunch?

• 3

• 6

• 9

• 12

Answer explanation

3 choices for dishes x 3 choices for drinks = 9 combinations

A standard number cube with numbers 1 through 6 is rolled. Find the probability of rolling a number greater than 2.

• 1/3

• 1/6

• 1/2

• 2/3

Answer explanation

The numbers 3, 4, 5, 6 are greater than 2. That is 4/6 numbers, which simplifies to 2/3.

Tags

CCSS.7.SP.C.7B

Justine decides to toss 2 coins 100 times. Which results should occur most often?

• Two heads

• Two Tails

• One head, One tail

• All are equally likely.

Answer explanation

I could get head/tail or tail/head. This is more likely than head/head or tail/tail.

Tags

CCSS.7.SP.C.6

Candice is the best hitter on her softball team. She gets on base 60% of the time. What is the probability that her next at bat will result in her getting on base?

• 3/5

• 1/6

• 1/2

• 2/5

Answer explanation

60% = 60/100 = 3/5 (Simplify.)

Tags

CCSS.7.SP.C.6

There are four students who will form a line. In how many different orders could they form a line?

• 4

• 8

• 16

• 24

Answer explanation

This is a countdown! 4x3x2x1=24

Jacob tosses a dice 24 times. About how many times would he expect to roll a 6?

• 2

• 4

• 3

• 5

Answer explanation

We can use a proportion! Remember one side of the dice has a 6!

1/6=x/24 (x=4)

Tags

CCSS.7.SP.C.6

A penny is flipped and a number cube is rolled. What is the probability that the penny lands heads up and a five is rolled?

• 1 out of 2

• 2 out of 12

• 1 out of 8

• 1 out of 12

Answer explanation

This is a compound event, so we need to multiply!

1/2 x 1/6 = 1/12

1/2 for heads and 1/6 for a five on the dice

Jay has a bag with 12 blue, 6 green, 8 purple, and 4 red marbles. If he wants to probability of picking a blue to be 1/2, what should he do?

• Add 2 green, 2 purple, and 2 red

• Add 2 blue

• Remove 1 green, 1 purple, 1 red

• Add 6 blue

Answer explanation

If we add 6 blue, the probability would be 18/36 = 1/2. Remember adding 6 blue changes the total number of marbles to 36!