Simple Probability Mastery Check Study Guide

If an event has a probability of 1, the event is...

• likely

• unlikely

• impossible

• certain

Answer explanation

An event with a probability of 1 is certain to occur. This means it will definitely happen, making 'certain' the correct choice. Other options like 'likely' or 'impossible' do not accurately describe this scenario.

Tags

CCSS.7.SP.C.5

Carmella rolls a number cube 12 times.

The number cube lands on 3 all twelve times.

What will happen on the next roll?

• The number cube will definitely land on 3.

• The number cube will definitely land on a different number (not 3).

• The number cube is more likely to land on 3 than the other numbers.

• There is an equal chance of the cube landing on any one of the six numbers.

Answer explanation

The outcome of each roll of a number cube is independent. Therefore, despite rolling a 3 twelve times, the next roll still has an equal chance of landing on any of the six numbers, including 3.

Tags

CCSS.HSS.CP.A.5

What is the probability of selecting an odd number from the bag?

• 1/3

• 3/4

• 1/2

• 1/12

Answer explanation

To find the probability of selecting an odd number, count the odd numbers in the bag and divide by the total numbers. If there are equal odd and even numbers, the probability is 1/2, making this the correct choice.

Tags

CCSS.7.SP.C.7B

What is the probability of rolling a 5 on a number cube?

• 5/6

• 1/6

• 1/5

• 1/2

Answer explanation

A number cube (die) has 6 faces, each showing a different number from 1 to 6. The probability of rolling any specific number, including a 5, is 1 out of 6 possible outcomes, hence the correct answer is 1/6.

Tags

CCSS.7.SP.C.7A

Grayson spins a spinner with sections that are numbered 1-9. Which outcome is impossible?

• Landing on an odd number

• Landing on a number less

  than 6

• Landing on a number greater than 11

• Landing on 3

Answer explanation

The spinner has numbers 1-9, so landing on a number greater than 11 is impossible. All other outcomes, such as landing on an odd number, a number less than 6, or landing on 3, are possible.

Tags

CCSS.7.SP.C.5

Michal is watching cars drive by from the window of his classroom. He has seen 2

red cars, 3 white cars, 5 black cars, and 8 blue cars drive by.

Which of the following probabilities is correct based on his observations?

• P(black car) = 1/18

• P(white car) = 1/10

• P(blue car) = 1/6

• P(red car) = 1/9

Answer explanation

To find the probability of seeing a red car, divide the number of red cars (2) by the total number of cars (2+3+5+8=18). Thus, P(red car) = 2/18 = 1/9, making this the correct choice.

Tags

CCSS.7.SP.C.7B

James wrote the names of his classmates on tickets and put them in a bag. He repeatedly drew a ticket, recorded the first letter of the name, and put the ticket back in the bag. The results were:

N, A, K, A, C, L, L, P, N, V, M, A

Based on the data, what is the probability that a student chosen at random from the class has a name that starts with L?

• 1/3

• 1/4

• 1/6

• 1/8

Answer explanation

In the results, 'L' appears 2 times out of a total of 12 letters. The probability of selecting a name starting with 'L' is therefore 2/12, which simplifies to 1/6.

Tags

CCSS.7.SP.C.6

This spinner is spun once. What is the probability the spinner will land on a number less than 5?

• 1/8

• 1/2

• 3/8

• 5/8

Answer explanation

The spinner has 8 equal sections. The numbers less than 5 are 1, 2, 3, and 4, totaling 4 favorable outcomes. Thus, the probability is 4/8, which simplifies to 1/2, making the correct answer 1/2.

Tags

CCSS.7.SP.C.7A

A student flips a coin 10 times and gets tails 7 times. Which of the following is a true

statement?

• The experimental probability and the theoretical probability are the same.

• The experimental probability is greater than the theoretical probability.

• The experimental probability is less than the theoretical probability.

• It is not possible to compare the experimental and theoretical probabilities.

Answer explanation

The student flipped the coin 10 times and got tails 7 times, giving an experimental probability of 0.7. The theoretical probability of tails is 0.5. Since 0.7 is greater than 0.5, the correct statement is that the experimental probability is greater.

If Sam were to conduct the same experiment with 200 draws, approximately how many times could he expect to draw a blue marble?

• 14

• 40

• 70

• 80

Answer explanation

If the probability of drawing a blue marble is 0.35, then in 200 draws, Sam can expect to draw approximately 200 * 0.35 = 70 blue marbles. Thus, the correct answer is 70.

Tags

CCSS.7.SP.C.6