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Probability
Math
Middle School Math

Name _____________________________

Date ___________________

Probability
Find the number of possible choices when you choose one item from each category.

1.	8 socks, 8 pairs of sunglasses, 7 shirts, 9 hats, 7 scarves

2.	* This is a pre-made sheet. Use the link at the top of the page for a printable page.

3.	3 desserts, 4 drinks, 3 vegetables

Find the probability. Write your answer as a fraction in simplest form.

1.	A number from 16 to 27 is drawn at random. P(a number divisible by 3).

2.	You roll a number cube numbered from 1 to 6. P(an even number).

Find the probability. Write your answer as a decimal rounded to the nearest hundredth.

1.	You roll a number cube numbered from 1 to 6. P(a composite number).

2.	A jar contains 23 green and 15 orange marbles. A marble is drawn at random. P(not orange).

Find the probability. Write your answer as a percent rounded to the nearest whole percent.

1.	A number from 14 to 22 is drawn at random. P(an odd number).

2.	A number from 15 to 22 is drawn at random. P(19).

Key #2

Find the probability.

1.	A number from 18 to 27 is drawn at random. P(21, 22, or 23) Express the probability as a fraction.

2.	You roll a number cube numbered from 1 to 6. P(6, 3, 5, or 1) Express the probability as a decimal. Round to the nearest hundredth.

Find the probability. Assume that the spinner is separated into equal sections.

1.	You flip a coin and toss a 1-6 number cube. P(tails and a number divisible by 2)

2.	You roll a number cube numbered from 1 to 6. You then spin a spinner with 3 sections each with a different color. The spinner has the colors orange, blue, and yellow. P(2 and blue)

Find the probability.

1.	There are 5 orange, 3 yellow, and 3 violet marbles in a hat. You pick 2 marbles from the hat. Marbles are not returned after they have been drawn. P(two yellow marbles in a row)

2.	A deck of cards has 3 orange, 4 purple, and 3 white cards. You pick 2 cards from the deck. Cards are not returned to the deck after they are picked. P(the first card is not orange and the second card is not white)

Find the probability. Assume that the spinner is separated into equal sections.

1.	A deck of cards has 5 brown, 5 black, 6 pink, 4 gray, and 2 yellow cards. You pick 2 cards from the deck. Cards are not returned to the deck after they are picked. P(the first card is black and the second card is gray)

2.	There are 6 navy, 5 blue, and 6 brown marbles in a hat. You pick 3 marbles from the hat. Marbles are returned after they have been drawn. P(three brown marbles in a row)

Key #2

Complete.

1.	How many two person committees can be chosen from a group of six people?

2.	How many three person committees can be chosen from a group of eight people?

Complete.

1.	In how many ways can Joseph, Michael, Christopher, Katherine, Rebecca, and Kyle stand in line?

2.	How many six digit numbers can you make by arranging the numbers 6, 9, 8, 3, 1, and 5?

Complete.

1.	There are 5 things in a hat. How many ways can you pick 2 things from the hat at once?

2.	How many combinations of two letters are possible from the letters V, A, and H?

Complete.

Brandon thinks of a whole number between nine and twenty. He then asks his mom to guess what number he is thinking of. Assuming Brandon is not known to have any number preference or predictable pattern to his number picking, what is the probability that his mom will correctly guess what number he is thinking of?

Stephanie bought a bag containing assorted hard candies from the local corner store. They were on clearance and she got a good deal. All the candies are the same size and shape but they are different colors and flavors. There are twelve blue ones, four red ones, three purple ones, fourteen green ones, and three orange ones. If the bag is shaken really well to mix the candy in the bag, what is the probability that the first candy she pulls out of the bag will not be green?

Key #2

Complete.

Mr. Bloop has discovered a new species of cactus in Bolivia. He goes to the location where they are found on the side of a mountain. He sees many specimens of the new species growing there. He collects some data on the color of the flowers produced by this cactus. He finds that thirty-one of the plants have purple flowers and twelve have white flowers. Now, assuming that the flower color ratio is the same everywhere in Bolivia for this plant, if he goes to another mountain side and collects similar data, what is the probability that the first plant he comes across will have white flowers? Write your answer as a percent rounded to the nearest tenth.

Last night, Alexandra counted the number of instant messages she received. She received five from Cody, ten from Alexandra, five from Brandon, seven from Isaac, and twenty-five from her best friend (and very chatty) Courtney. She turned on her computer. What is the probability that the first instant message she receives is from Courtney?

Complete.

1.	Mr. Snorp is sending teams of math superstars from his school to a mathematics contest in Bigtown. He has fourteen students to choose from and the teams must consist of two people. How many ways are there for him to choose different two person teams from his fourteen candidates?

2.	Proteins are made from linear sequences of amino acids. How many different proteins could be made from the amino acids phenylalanine, glutamic acid, and lysine?

Complete.

1.	There are four black marbles, seven red marbles and nine white marbles in a bag. The first marble selected at random from the bag is red. The red marble is not put back in the bag. What is the probability of pulling out a red marble on the next try?

2.	You have seven pennies, ten nickels and three dimes in a piggy bank. If you turn the bank upside down and shake it until a coin comes out of the slot, what is the probability that you will get out two pennies in a row?

Answer Key

Sample
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Probability
Math
Middle School Math