Geometry | Unit 8 | Lesson 11: Probabilities in Games | Practice Problems

The two-way table shows the number of eggs laid by 10 Rhode Island red chickens and 10 leghorn chickens in July and August.

	eggs laid in July	eggs laid in August
Rhode Island red chicken	247	252
leghorn chicken	239	241

A chicken is selected at random. For each question, Event A is “egg laid by a Rhode Island red chicken” and Event B is “egg laid in July.” Use the data to estimate the probabilities.
P(A)
P(B)
P(A and B)
P(A | B)
Use P(A | B) = P(A) and P(A and B) = P(A) ⋅ P(B) to determine if the two events are dependent or independent. Show or explain your reasoning.

Tags

CCSS.HSS.CP.A.4

CCSS.HSS.CP.A.2

Clare finds an article in the online student newspaper that says, “There are more students in the 9th grade this year than last year and there are more students in the 12th grade who are graduating this year than last year.” Are the events “the number of students in the 9th grade” and “the number of 12th graders who are graduating” dependent or independent events? Explain your reasoning.

Tags

CCSS.HSS.CP.A.5

The two-way table summarizes whether or not a softball team had practice when it was raining and when it was not raining at the start of the day.

	softball practice	no softball practice
raining	4	1
not raining	12	3

When it was raining at the start of the day, what is the probability that softball practice was held?
When it was not raining at the start of the day, what is the probability that softball practice was held?
Are the events of “holding softball practice” and “raining at the start of the day” dependent or independent events? Explain your reasoning.

Tags

CCSS.HSS.CP.A.4

Mai rolls a standard number cube and then flips a fair coin. What is the probability that Mai flips heads under the condition that she rolls a 5?

Tags

CCSS.HSS.CP.B.6

Tags

CCSS.HSS.CP.B.7

Two classes of middle school students who are going on a field trip were asked if they wanted to go to a science museum or an art museum. Each student selects one museum option. The table summarizes the museum preference of each student in the class.

	science museum	art museum
class A	14	12
class B	11	14

What is the probability that a student in class B selected at random prefers to go to the art museum?

Tags

CCSS.8.SP.A.4

Elena decides which type of pizza to order. The choices for crust are thin crust, stuffed crust, or regular crust. The choices for one topping are pepperoni, mushrooms, olives, sausage, meatballs, pineapple, or green peppers. Elena has trouble deciding because there are so many possibilities. She selects the type of crust and one topping at random. How many outcomes are in the sample space?

• 3

• 7

• 10

• 21