Probability
Probability Terminology
Why Not?
Probability in Greatness
Surprise Me!
100
Bruce is going to call one person from his contacts at random. He has 25 total contacts. 20 of those contacts are from his neighborhood. What is the probability that he calls a person NOT from his neighborhood?
5/25 = 0.2
100
Name given to events that cannot happen at the same time?
Mutually Exclusive Events
100
In a lottery, there are 10 prizes and 25 blanks. A lottery is drawn at random. What is the probability of getting a prize?
10/35 = 2/7
100
A fair 6-sided die is tossed twice. Find the probability of getting a 4 or 5 on the first toss and a 1, 2, or 3 in the second toss.
1/3 * 1/2 = 1/6
100
If A and B are mutually exclusive events, what is P(A or B)?
P(A) + P(B)
200
If I roll a fair 6-sided die, what is the probability that I roll an odd number? (Odd means NOT divisible by 2)
P(odd) = 3/6 = 1/2
200
Can mutually exclusive events be independent of each other?
Yes! Independent events don't have to happen together.
200
A card is drawn from a pack of 52 cards. The probability of getting a queen of club or a king of heart is:
1/52 + 1/52 = 2/52 = 1/26
200
If I have a deck of 52 cards, what is the probability that I draw 3 Aces in a row? (without putting any cards back) Answer as a product of terms.
4/52 * 3/51 * 2/50
200
There is a party tonight. If my crush goes to the party, then there is a 90% chance that I will go too. If my crush doesn’t go to the party, then there is only a 50% chance that I will go. I find out that there is a 40% chance that my crush will go to the party tonight. Now what is the probability that I will go?
66%. 0.4 * 0.9 + 0.6 * 0.5 = .36 + .3 = .66
300
A standard deck contains 52 cards. If a card is flipped over, what is the probability that it is a a face card (J, Q, K) of any suit?
12/52 = 3/13
300
The name of the diagram that represents a universal set?
Venn Diagram
300
In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?
7/21 = 1/3
300
What is the probability that the total of two dice will be greater than 8, given that the first die is a 6?
2/3
300
How many numbers between 1 and 100 (inclusive) are divisible by 3 or 10?
43 - 3 = 40
400
I flip 3 fair coins. What is the probability that I get exactly 2 tails?
3/8
400
If P(B|A) = P(B), B and A are mutually exclusively events. True or False or You Don't Know?
You Don't Know. Not enough information given
400
A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?
5/7 * 4/6 = 10/21
400
The probability that a student passes math is 2/3 and the probability that he passes English is 4/9. If the probability that he will pass at least one subject is 4/5, what is the probability that he will pass both subjects?
(2/3) + (4/9) - (4/5) = 14/45
400
A natural number is chosen randomly, the probability that the number is a real number is?
1 because all natural numbers are Real Numbers!
500
I throw 8 fair coins, how many possible events are in the sample space?
2^8 = 256
500
Upon throwing two dice, the probability of getting a sum of 5 when I add the two numbers together is 1/6. Are both dice fair?
No. If they were, the probability would have been 1/9
500
Two dice are thrown simultaneously. What is the probability of getting two numbers whose product is even?
1 - 9/36 - 27/36 = 3/4
500
You have the numbers 1-10 and you are asked to pick one number. What is the probability that it is not a prime number and it is a complex number?
6/10*1=3/5
500
10 distinct positive whole numbers are randomly chosen, the probability that the median of the ten numbers is among the ten numbers is?
0
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