Probability

Question 1

You have a pair of blue pants and a pair of black pants in your closet. You also have a red shirt, a white shirt, and a plaid shirt. You don’t like black pants with a plaid shirt or the white shirt what is the probability that you will choose an outfit that you like

Answer 1

blue pants black pants
white shirt white shirt
plaid shirt plaid shirt
red shirt red shirt

there is a 4/6 probability

Question 2

There are 5 red blocks, 7 green, 0 blue, and 6 yellow what is the probability of picking each

Answer 2

P= n(a)/ n(t) P= 5/18= 27.77 red

P=n(A) /n(T) P= 7/18 = 38.9 green and blue

P=n(A)/n(T) P=6/18=33 yellow

Question 3

What is odds in favor

Answer 3

A=P(A)/P(A1)

Question 4

What is odds against

Answer 4

A=P(A1)/ P(A)

Question 5

An analyst says the Canadian women’s hockey team has a 75% probability f winning a gold medal in the next Olympics. What are the odds in favor of the team winning gold?

Answer 5

P(A)/P(A1)

=75/25

=3/1

Question 6

A golfer has a 20% chance of winning a tournament. What are the odds against the golfer winning?

Answer 6

P(A1)/P(A)

=80/20

=4/1

Question 7

Your pencil case has 8 pens and 4 pencils. What are the odds of randomly drawing a pencil?

Answer 7

n(A)/ n(A1)

=4/8

=1/2

Question 8

The odds of passing a course are 8~1 when a student misses fewer than 6 classes. What is the probability that a student with good attendance will pass the course?

Answer 8

P=n(pass)/n(s)

=8/9

Question 9

what is the probability of rolling a 4 on six sided die?

Answer 9

PA=n(a)/n(S) S=sample space
PA=1/6

S={1,2,3,4,5,6}

Question 10

What is the probability of rolling an odd number on a six-sided die?

Answer 10

PA=nA/nS

PA= 3/6=1/2

A{1,3,5}
S{1,2,3,4,5,6}

Question 11

What is the probability of pulling a green marble from a bag containing 20 marbles? 4 blue, 6 orange, 7 green, 3 purple

Answer 11

PA=n(A)/n(S)=7/20
A{green}
S{b, o, g, p}

Question 12

What is the probability of drawing any card other than an ace out of a well shuffled deck?

Answer 12

P(A’)=1-P(A)
P=(ace) P(ace’)

n(ace)/n(cards)

P=4/52

=/7%

1-P(ace) 1-7%

100-7=93
P(ace’) =93%

Question 13

A coin is tossed and a die is flipped. Find the probability of flipping heads and then rolling a 6

Answer 13

P(heads,6)= 1/2 *1/6 = 1/12

Question 14

the probability that Crosby gets a point in a game is 85% find the probability that he gets a point in three consecutive games.

find the probability that Crosby gets no points in 3 consecutive games

Answer 14

P(point)(point)(point) =P(point)(point)(point)

=(0.85)(0.85)(0.85)=0.624=61.4

P(A’)/P(A)
=0.150.150.15=0.34=34%

Question 15

find the probability that he gets a point in at least one of the three games

Answer 15

P=(point in at least one game)= 1-P(point in no games) 1-0.0034= 99.66