# Worksheet: Finding Probability Using Combinations

Q1:

Find the number of ways to select 3 different letters from the set .

Q2:

How many teams of four can be selected from a group of 20 people?

Q3:

A team of four is to be randomly selected from a group of ten boys and ten girls. Determine the probability that a team will contain only girls.

• A
• B
• C
• D
• E

Q4:

Seven boys and eight girls entered a draw for four free movie tickets. What is the probability that all four tickets were won by boys?

• A
• B
• C
• D
• E0

Q5:

Which of the following represents the number of ways of selecting 2 students out of 24 for a class activity?

• A
• B
• C
• D

Q6:

Which of the following represents the number of ways of selecting 2 students out of 17 for a class activity?

• A
• B
• C
• D

Q7:

A computer generates four-digit codes using the numbers 0–9 with no repeated digits. How many unique codes can be generated?

Q8:

A small combination padlock can be opened by entering three different specified numbers from 1 to 9 in any order. Noah has 10 attempts to guess the combination. Determine the probability of him opening the lock.

• A
• B
• C
• D
• E

Q9:

A bowl contains 25 marbles, each with a different color. If Liam selects four marbles from the bowl, what is the probability that he selects the marbles with the four colors that he wants?

• A
• B
• C
• D
• E0

Q10:

Madison wants to visit cities across the US, and she has placed the names of 32 cities into a hat. If she randomly draws 3 names from the hat, what is the probability that she gets Savannah, Austin, and Seattle?

• A
• B
• C
• D
• E0

Q11:

Thirteen boys and fifteen girls entered a draw for five free movie tickets. What is the probability that all five tickets were won by boys?

• A
• B
• C
• D
• E0

Q12:

Amelia invited 4 of her 24 friends over for a movie night. If she chose to invite her friends at random, what is the probability that Jennifer, Charlotte, Scarlett, and Olivia are chosen?

• A
• B
• C
• D
• E0

Q13:

In how many different ways can 10 motorcycles and 9 bicycles be arranged in 2 spaces if the order is not important?

Q14:

In a science fair experiment, three units are selected for testing out of every 587 units produced. In how many ways can these three units be selected?

Q15:

In a science fair experiment, three units are selected for testing out of every 517 units produced. In how many ways can these three units be selected?