Simple Probabilities
What is the probability of rolling a 2 when a die is rolled once?
1/6
When a single card is drawn from a deck of cards, what is the probability of getting a 5 or a king?
P(5) + P(king)
= 4/52 + 4/52
= 8/52 or 4/13
A n B
What does "n" refer to?
intersection
How many outcomes are possible from a choice of jeans or khaki shorts and a choice of a yellow, white, or blue shirt.
6 possible outcomes
What is the probability of rolling an even number when a die is rolled once?
1/2
When a single card is drawn from a standard deck of cards, what is the probability of getting a 2 or a red card?
P(2) + P(R) - P(2 and R)
= 4/52 + 26/52 - 2/52
= 28/52
A u B
What does "u" refer to?
union
What are the possible outcomes of apple, peach, or cherry pie with milk, juice or tea?
9 outcomes
What is the probability that a card drawn at random from a deck will be an ace?
4/52 = 1/13
The probability that a person owns a iPhone is 0.75, that a person owns a Android is .25 and that a person owns both a iPhone and a Android is 0.16. Find the probability that a person owns either a iPhone OR a Android.
P(I) + P(A) - P(I and A)
= .75 + .25 - .16
= .84
What does A1 refer to?
"A prime"; everything but A
How many ways can 2 video games be chosen from 5 video games?
10 ways
What is the probability that when a pair of dice are thrown, the sum of the numbers equal 5?
4/36 = 1/9
You have a bag of 24 marbles. 8 marbles are blue, 9 red marbles, 5 are green and 2 are yellow. Find P (Red or Yellow).
11/24
What does mutually exclusive event mean?
Events that cannot happen at the same time.
Dice roll - Cannot roll both an even number and an odd number
How many ways can a person choose to watch two TV shows from four TV shows?
5 ways
A book contains 32 pages numbered 1-32. If a student randomly opens the book, what is the probability that the page number is a multiple of 5?
6/32 = 3/16
Which of these numbers cannot be a probability?
a) -0.00001 b) 0.5 c) 1.001 d) 0 e) 1 f) 20%
A and C
What does complementary event mean?
Events that are the only two possible outcomes.
Tossing a coin - you can only get heads or tails
A coin is tossed three times. How many outcomes are possible?
8 outcomes