Practice for Probability Retest

Ernest is playing a board game with Calley that uses the spinner below. If the spinner is spun twice, which tree diagram shows all possible outcomes the pointer can land on during both spins? (Circle the correct letter.)

• A

• B

• C

• D

Cindy is playing a card game with her brother. Three of the cards she has are 7s, three other cards are 8s, and two of the cards are 9s. If Cindy lays the cards facedown, and her brother selects one card, what is the probability the card he selects is not an 8? (Show your work and write your final answer.)

Mathematical Equivalence

ON

Answer explanation

Three 7s,

three 8s

two 9s

8 = 3/8 chance

Not 8 = 5/8

The forecast for rain today is 95%. The chance of rain is ​ (a)   . (Choose the correct word.)

• likely
• certain
• possible
• unlikely

Jenna wants to draw a picture. She has 4 crayons, 3 markers, and 3 colored pencils. If she plans to draw her picture with only 1 crayon, 1 marker, and 1 colored pencil, how many possible combinations can she choose from?

Mathematical Equivalence

ON

Answer explanation

{C1 M1 CP1; C1 M1 CP2; C1 M1 CP3; C1 M2 CP1; C1 M2 CP2; C1 M2 CP3; C1 M3 CP1; C1 M3 CP2; C1 M3 CP3; C2 M1 CP1; C2 M1 CP2; C2 M1 CP3; C2 M2 CP1; C2 M2 CP2; C2 M2 CP3; C2 M3 CP1; C2 M3 CP2; C2 M3 CP3; C3 M1 CP1; C3 M1 CP2; C3 M1 CP3; C3 M2 CP1; C3 M2 CP2; C3 M2 CP3; C3 M3 CP1; C3 M3 CP2; C3 M3 CP3; C4 M1 CP1; C4 M1 CP2; C4 M1 CP3; C4 M2 CP1; C4 M2 CP2; C4 M2 CP3; C4 M3 CP1; C4 M3 CP2; C4 M3 CP3}

36 choices

Nick bought a package of jawbreakers containing 4 blue, 3 red, 2 green, and 3 yellow jawbreakers. He gave 1 blue, 1 red, and both green jawbreakers to his brother. If Nick now selects 1 jawbreaker without looking, what is the probability he will not select a blue jawbreaker? (Show your work)

Mathematical Equivalence

ON

Answer explanation

The total number of jawbreakers remaining is: 3 blue+2 red+0 green+3 yellow=8 jawbreakers3 blue+2 red+0 green+3 yellow=8 jawbreakers

Now, let's find the probability of not selecting a blue jawbreaker:

Probability of not selecting a blue jawbreaker = 2 red+3 yellow8 total jawbreakers8 total jawbreakers2 red+3 yellow​

Probability of not selecting a blue jawbreaker

So, the probability that Nick will not select a blue jawbreaker is 5/8

1. It's dinner out tonight. At a restaurant, for the meal, you can choose between pizza, pasta. For drinks, you can choose between tea, ginger ale, and cola. Write the sample space.

Answer explanation

{Pizza Tea; Pizza Ginger Ale; Pizza Cola; Pasta Tea; Pasta Ginger Ale; Pasta Cola}

Same for: A 2-sided spinner colored blue and red is spun and then a 4-sided spinner with numbers 1-4 on it is spun. Write the sample space. How many possible outcomes are there?

Mathematical Equivalence

ON

Answer explanation

{Blue 1; Blue 2; Blue 3; Blue 4; Red 1; Red 2; Red 3; Red 4}

There are 8 possible outcomes.

1. The teacher asks you to read 4 books: “Poison”(P), “Midsummer Night's Dream”(M),“The Swan”(S), and Harry Potter (H). Find all of the different possibilities of reading order. How many different combinations are possible (Order matters) 

• 12

• 24

• 36

• 72

Answer explanation

{PMSH, PMHS, PSHM, PSMM, PHMS, MPSM, MSPH, MHPS, MHSP, MSHP, MSMP, HPSM, HSPM, HPMS, HMSP, HSMP, SHPM, SMPH, SHMP, SMHP, SPHM, SPMM, HSMP}

1. There are 20 students in the classroom, 12 girls and 8 boys. Find the probability that one girl will be picked from the class. (Please use the proper notation: P(E) =)

• 1. P(E) = 3/5

• 1. 3/5

• 1. P(1 girl) = 2/5

• 1. P(1 girl) = 3/5

If a standard deck of cards is shuffled, what is the probability of drawing a red card? (Please use the proper notation: P(E) =)

• 13/52

• P(Red) = 13/52

• P(Red) = 26/52

• P(E) = 26/52