Simple Probability
A spinner has equal sections numbered 1-6. What is the probability of spinning a 3?
1/6 or 0.1666... or 16.7%
What is the probability of rolling two odd numbers in a row with a standard number cube?
3/6 xx 3/6 = 1/4 = 25%
How many ways can we order a four topping pizza if there are seven toppings to chose from?
7C4
(7xx6xx5xx4)/(4xx3xx2xx1)
35
How many ways can a club of 12 people select a president, a vice-president, and a secretary?
12P3
12 x 11 x 101,320
You choose a card from the cards of destiny. What is the probability of choosing a multiple of 3?
3, 6, 9, or 12
4/12 = 1/3 = 33.bar3%
Maria is flipping a coin and spinning a spinner. The spinner has 4 equal sections labeled A-D. What is the probability the coin will land on heads and the spinner will land on the letter "A"?
1/2 xx 1/4 =
1/8 or 0.125, or 12.5%
There is a school raffle this week, the first prize is a coffee mug, the second prize is a picture frame, and the third prize is a candy bar. How many ways can you hand out the prizes in 100 students entered the raffle?
100P3
100 x 99 x 98
970,200
How many ways can you arrange the starting 5 players on a basketball team of 8 players? Each player has a unique position
8P5
8 x 7 x 6 x 5 x 4
6,720
A bag of jolly ranchers has 7 apple, 8 blue raspberry, 10 grape, and 5 cherry.
If you pick at random, what is the probability of getting cherry?
1/6 or 0.166... or 16.7%
The classic wood carousel at Carousel Park in Hampton, VA has 32 jumping horses and 16 standing horses.
What is the probability of randomly selecting a jumping horse first and then selecting a standing horse?
2/9 or 0.22... or 22.2%
To open your locker, you must dial a sequence of three numbers called the lock’s combination. Given that there are 40 numbers on a lock, how many different locker combinations are there if you can repeat the same numbers?
403
640,000
For lunch today, a student can choose between a hamburger or a turkey burger. There are four different types of cheese, three choices of condiments, and 3 choices for breads. If a student chooses one of each category, how many different ways can the student make their lunch?
2 x 4 x 3 x 3
72
A grocery store has 4 raspberry yogurts, 6 strawberry yogurts, and 2 vanilla yogurts.
If you pick a yogurt at random, what is the probability of getting a red fruit?
10/12 = 5/6 = 83.bar3%
There are 3 red marbles, 2 green marbles, and 1 yellow marble in a box. One marble is taken out and not replaced. A second marble is then taken out and not replaced. What is the probability both marbles that were taken out are red?
1/5, or 0.20, or 20%
A college student has to take a math class, a science class, and a business class. How many choices does she have if there are 5 math classes, 4 science classes, and 6 business classes to choose from?
5 x 4 x 6
120
Mia needs to create a 4-digit password to log into a website. The rules state the first two must be letters and the second two must be numbers. Repetition is allowed. How many codes are there?
26 x 26 x 10 x 10
67,600
Tim's book collection contains 20 books. Five are biographies, 11 are fiction, and the rest are poetry.
If Tim randomly selects a book to read, what is the probability that it will be a biography or poetry?
4 are poetry, so:
(5+4)/20 = 9/20 = 45%
2/24 xx 1/23 = 1/276
Gertrude's lockscreen on her phone is a 6-digit number. She chose a code where all digits are greater than 3, and there are no repeating digits. How many codes are possible?
6 x 5 x 4 x 3 x 2 x 1
720
Roger has to pack for vacation. His suitcase is almost full, but he needs to add some more shirts. He has 10 shirts to choose from, but he can only fit another 4. How many choices does Roger have?
10C4
(10xx9xx8xx7)/(4 xx 3 xx 2 xx1)
210