Misc Probability
Conditional Prob
Expected Value
Odds
100
Use the table to find the probability that a randomly chosen person has black eyes if we know the person is female.
P(black eyes | female)= ?
What is 20/85 or 4/17 or 24%?
100
In a class with 30 students, 19 are honor students, 12 are athletes and 9 are both honor and athlete. The probability that a randomly selected student is an athlete if it is known that he/she is an honor student is __.
What is 9/19?
100
The expected number of heads when flipping 5 coins is __.
What is 2.5?
100
The probability of rain is 22%. The odds of rain are __. (Express odds with colon notation.)
What is 11:39?
( 22:78, if not reduced)
200
If the odds against rain is 3:5, then the probability of rain is __.
What is 5/8?
200
In a club with 100 students, 80 are women, 62 are bicyclists, and 50 are women bicyclists. The probability that a student is a bicyclist if it is known that the student is a woman is __.
What is 50/80 or 5/8?
p(bicyclist | woman)
=p(bicyclist and woman)/p(woman)
=50/80
200
The expected outcome when rolling two dice and adding the tops is __.
What is 7?
200
The odds of a given horse winning a race is given as 3:17. The probability the horse will win is __.
What is 3/20 or 15%?
300
If the probability of having a boy is 107/207, then the probability of a family having three children all of whom are boys is __. (Express as a percent, round to nearest percent.)
What is 14%?
300
Use the table below to find the probability that a randomly selected candy is a jawbreaker given that it is not red.
What is 30/50 or 3/5?
p(Jaw | not red)=p(jaw and not red)/p(not red)
=30/50
300
A raffle gives one first place prize of $500, 4 second place prizes of $100, and 10 third place prizes of $25. If 3000 tickets are sold, the expected value of a ticket is __.
What is $0.38 or 38 cents?
300
The probability of getting exactly 2 heads when flipping three coins is 3/8. The odds of getting exactly 2 heads is __.
What is 3:5?
400
If a bag has 3 red marbles and 4 blue, and two marbles are pulled out without replacement, the probability that both marbles are the same color is __.
What is 18/42 or 3/7 ?
2 red or 2 blue
(3/7)(2/6) + (4/7)(3/6)
6/42 + 12/42 = 18/42
400
If we know a randomly chosen candy from the table below has nuts, find the probability it is a caramel.
What is 11/24?
400
A raffle gives one first place prize of $500, 4 second place prizes of $100, and 10 third place prizes of $25. If 3000 tickets are sold for $1 each, the total profit earned in the raffle is __.
What is $1850?
Profit=Revenue minus Prizes
=($1)3000. - [(1)$500+(4)$100+(10)$25]
=$3000 - $1150 = $1850
400
The probability of getting a full house in a 5-card poker hand is 6/4165. The odds against getting a full house is __.
What is 4159:6?
500
Use the given table of data to find the probability a person chosen at random has a cat if we know the person is male.
What is 10/52 or 5/26 or 19.23% ?
p(cat | male) = p(cat and male)/p(male)
=10/52
500
Using the Venn diagram below, find the probability that a randomly selected student takes math if it is known that he doesn't take English.
What is 50/100 or 1/2?
500
A concert producer is projected to make $100,000 at an outdoor concert if it doesn't rain, but only $30,000 if it does rain. The probability of rain on the day of the concert is 20%. The expected profit for the producer is __.
What is $86,000?
500
The odds against graduating from a certain high school are 3:29. The probability of graduating from that high school is __.
What is 29/32?