Real-world events
If you roll two fair six-sided dice, what is the probability that the dice show the same number?
1/6
f you roll two fair six-sided dice, what is the probability that the sum is 5 or lower?
The probability that the dice add to 5 or lower is 10/36
James lives in San Francisco and works in Mountain View. In the morning, he has 3 transportation options (bus, cab, or train) to work, and in the evening, he has the same 3 choices for his trip home.
If James randomly chooses his ride in the morning and in the evening, what is the probability that he'll take the same mode of transportation twice?
3/9 or 1/3
If you flip three fair coins, what is the probability that you'll get two tails and one head in any order?
3 out of 8
You're at a clothing store that dyes your clothes while you wait. You get to pick from 4 pieces of clothing (shirt, pants, socks, or hat) and 3 colors (purple, blue, or orange).
If you randomly pick the piece of clothing and the color, what is the probability that you'll end up with socks that aren't blue?
2/12 or 1/6
You're having dinner at a restaurant that serves 5 kinds of pasta (spaghetti, bow ties, fettuccine, ravioli, and macaroni) in 4 different flavors (tomato sauce, cheese sauce, meat sauce, and olive oil).
If you randomly pick your kind of pasta and flavor, what is the probability that you'll end up with bow ties, cheese sauce, or both?
The probability of randomly picking one of those dishes is 8 out of 20, or 8/20. We can simplify this fraction to 2/5.
Justin lives in Saint Paul and goes to school in Minneapolis. In the morning, he has three transportation options (bus, cab, or train) to school, and in the evening, he has the same three choices for his trip home.
The probability that Justin will use both the bus and the train is 2 out of 9
If you roll two fair six-sided dice, what is the probability that at least one die shows a 3?
11/36
If you flip three fair coins, what is the probability that you'll get all three tails?
1/8
You're playing a game where you defend your village from an orc invasion. There are 3 characters (elf, hobbit, or human) and 5 defense tools (magic, sword, shield, slingshot, or umbrella) to pick from.
If you randomly choose your character and tool, what is the probability that you'll be a magic elf?
1/15
Elizabeth lives in San Francisco and works in Mountain View. In the morning, she has three transportation options (a bus, a cab, or a train) to work, and in the evening, she has the same three choices for her trip home.
If Elizabeth randomly chooses her ride in the morning and evening, what is the probability that she'll use a cab exactly once?
The probability that Elizabeth will use a cab once is 4 out of 9.
If you flip three fair coins, what is the probability that you'll get at least two heads?
The probability of getting at least two heads is 4 out of 8
If you flip three fair coins, what is the probability that you'll get heads on the first two flips and tails on the last flip?
The probability of getting heads on the first two flips and tails on the last flip is1/8
You've decided you want a plant for your room. At the gardening store, there are 4 different kinds of plants (tulip, fern, cactus, and ficus) and 4
different kinds of pots to hold the plants (clay pot, plastic pot, metal pot, and wood pot).
If you randomly pick the plant and the pot, what is the probability that you'll end up with a tulip in a plastic pot?
The probability of randomly picking a tulip in a plastic pot is 1 out of 16
You're playing a game where you defend your village from an orc invasion. There are 3 characters (elf, hobbit, or human) and 5 defense tools (magic, sword, shield, slingshot, or umbrella) to pick from.
If you randomly choose your character and tool, what is the probability that you won't be a hobbit or use an umbrella?
8 out of 15
If you roll two fair six-sided dice, what is the probability that the sum is 9 or higher?
10/36 or 5/18