Compute the probability of equally likely outcomes
If I place 5 coins of colors (red, blue, pink, purple, & orange) into a hat, what is the probability I pick a pink coin?
The coins are the same size and weight. You are only picking once and then putting the coin back.
1⁄5
If you are at the Super Bowl and get chosen for the coin toss, what is the probability it lands on heads?
1⁄2
You get to pick out 3 diamonds for your engagement ring. Out of the 10 diamonds, you’re looking at 5 that are fake diamonds.
What is the probability you pick 3 real diamonds for your ring?
10⁄120
You need to create a 3-digit code with numbers 0 through 9.
What is the probability you don’t repeat a number in your code?
720⁄10,000
In the sample space {1,4, 22,6, 10, 58, 64, 72}, what is the probability of selecting an even number?
Use Complement rule to solve.
7⁄8
If I have 4 unique possible outcomes with equally likely chances of occurring that are apart of my sample, what is the probability 1 unique outcome occurs?
1⁄4
If Sarah throws a beach ball at you, what is the probability your right thumb lands on red or blue?
There are 6 colors on the beach ball that take up the exact same area and do not overlap.
2⁄6
You’re celebrating easter and can pick 2 eggs from a basket of 6 total eggs. 3 eggs contain $5, and the rest contain $1.
What is the probability you select 2 easter eggs that have $5?
3⁄15
A talent show has 4 performers - Jack, Sarah, Dan, and Laura.
What is the probability Laura goes first and Dan is second?
6⁄24
For dessert, Sarah will have chocolate ice cream 20% of the time, vanilla cake 40% of the time, or she will have a brownie.
What is the probability Sarah will have a brownie for dessert?
.40 or 40%
If I have soccer balls labeled {1, 2, 3, 4, 5} in a bag, what is the probability I pick an even number ball?
2⁄5
You are approaching a stoplight without knowing the current color of the light, what is the probability the light is not red?
Use Complement rule to solve.
2⁄3
Your gym teacher needs to make a basketball team from a class of 10 boys and 5 girls.
What is the probability the team has 2 boys and 3 girls?
45⁄3003
You’re in a class of 15 people. What is the probability your class president, your friend Jack is Vice president, and Sarah is secretary if it is picked by random and in that order?
1⁄2730
You take a survey of your class that has 30 students who own a dog or cat. There are 6 people in your class that have both a dog and a cat.
What is the probability students do not own both a cat and dog?
Use Complement rule to solve.
.80 or 80%