Basic Probability
Jenny rolls a standard 6-sided die. What is the probability that it will land on an even number?
1/2
Your teacher gave you a bowl of colored jellybeans. The jar contains 5 red jellybeans, 10 black jellybeans, and 15 orange jellybeans. If two jellybeans are chosen, with replacement, what is the probability that both jellybeans will be red?
1/36
The letters that form the word “PROBABILITY” are placed in a bowl. If a letter is randomly chosen, not replaced, then another letter is randomly chosen, what is the probability that the first letter is a Y and the second letter is an R?
1/110
Jack looks in his closet and notices that he has 3 different shirts, 2 different pairs of jeans, and 6 different pairs of shoes. If an outfit consists of a shirt, a pair of jeans, and a pair of shoes, how many unique outfits could Jack create?
36
You have a spinner that is divided into 5 equal parts, labeled with the numbers 1-5. If you spin the spinner 30 times, about how many times could you expect the spinner to land on the number 3?
6
Jeremy has a bag of 20 marbles. 5 are blue, 7 are green, 2 are red, and 6 are yellow. If Jeremy reaches in the bag and randomly selects a marble, what is the probability that it is not green?
13/20
If you flipped a coin and rolled a 6-sided die, what is the probability that you will flip a heads and roll an even number?
1/4
A jar contains 10 caramels, 5 mints and 15 dark chocolates. What is the probability of selecting and eating a dark chocolate and then a caramel?
5/29
In your closet, you have 3 shirts, 2 pair of jeans, 3 pairs of shoes, and 2 hats. If an outfit consists of a shirt, a pair of jeans, a pair of shoes, and a hat, how many different combinations could be created?
36
If you roll a fair die 500 times, about how many times can you expect to roll an even number?
250
In your wallet you have the following paper money: 3 one dollar bills, 4 five dollar bills, 2 ten dollar bills and 6 twenty dollar bills. What is the probability if you give one of the bills to the Salvation Army guy ringing the bell as you exit Wal-Mart that you will NOT give him a twenty?
3/5
A cooler contains 5 sodas, 6 bottles of water, 2 Gatorades, and 3 juice boxes. If you were to reach in the cooler and randomly select a drink, calculate P(bottle of water)
3/8
A classroom consists of 24 students, 12 boys and 12 girls. If two students are randomly selected from the class to go to lunch early, what is the probability that the first student selected is a girl and the second student selected is a boy?
6/23
For lunch, there are five different types of sandwiches, three different bags of chips, two choices of beverage, and three desserts. If a meal is made up of a sandwich, a bag of chips, a beverage, and a dessert, how many distinct combinations could be formed?
90
A fair die is rolled 70 times. About how many times could you expect it to land on an odd number?
35
Ten balls are placed in a bucket. Three are red, four are blue and three are yellow. If Jim randomly selects one ball from the bucket, what is the probability that he will select a red ball?
3/10
Two fair dice are thrown. What is the probability that the first die rolls a 1 and that the second die rolls an even number?
1/12
A goblet contains 2 red marbles, 6 green marbles, and 4 blue marbles.
If we choose a marble, then another marble without putting the first one back in the goblet, what is the probability that the first marble will be green and the second will be green as well?
5/22
If you flip three fair coins, how many possible outcomes are there?
8
When a coin is flipped three times, what is the probability of getting heads three times in a row?
1/8
Each number 1-30 is written on a card and each card is turned face down. If you were to randomly select one card, what is the probability that you would select a card with a number greater than 20?
1/3
Captain Gabriela has a ship, the H.M.S. Khan. The ship is two furlongs from the dread pirate daniel and his merciless band of thieves.
The captain has the probability of 1/2 of hitting the pirate ship.
The pirate has only one good eye, so he hits the Captain's ship with a probability of 1/5.
If both fire their cannons at the same time, what is the probability that both the pirate and the Captain hit eat other's ships?
1/10
Captain Emily has a ship, the H.M.S Crimson Lynx. The ship is four furlongs from the dread pirate Ashley and her merciless band of thieves.
If her ship hasn't already been hit, Captain Emily has a probability 1/2 of hitting the pirate ship. If her ship has been hit, Captain Emily will always miss.
If her ship hasn't already been hit, dread pirate Ashley has a probability 1/6 of hitting the Captain's ship. If her ship has been hit, dread pirate Ashley will always miss.
If the Captain and the pirate each shoot once, and the Captain shoots first, what is the probability that the Captain hits the pirate ship, but the pirate misses?
1/2
You go to Chili's and want to get the 3 for $10. You have 3 drink options, 6 appetizer options, and 8 entree options. How many possible different meals are there to choose from that have 1 drink, 1 appetizer, and 1 entree?
144
Molly is given the option to pick Door #1, Door #2, and Door #3 on a game show. Behind one of the doors is a vacation, and behind the other two are garbage bags. She decides to pick Door #1. The host of the show proceeds to show Molly that there is garbage behind Door #3 and then gives Molly the option to switch her choice. Should Molly switch from Door #1 to Door #2? (Hint: this is based on probability)
Yes. Her chances are higher for winning if she switches door choices.