Probability Review
Questions 1-4 are based on the Scenic Railroad tree diagram.
1. What is the probability of choosing an adult ticket on a Saturday or Sunday?
4
1
P(Adult on Sat/Sun)= 12 = 3
2. What is the probability of choosing a full day child’s ticket?
2
1
P(Full day child) = 12 = 6
3. What is the probability of choosing a half day Saturday ticket?
3
1
P(Saturday half day) = 12 = 4
4. What is the probability of choosing a full day senior’s ticket on a Sunday?
1
P(Sunday full day senior) = 12
5. What is the probability of choosing a king from a standard deck of playing cards?
4
1
P(king) = 52 = 13
6. What is the probability of choosing a green marble from a jar containing 5 red, 6 green and 4 blue marbles?
6
P(green) = 15
7. What is the probability of choosing a marble that is not blue in problem 2?
9
P(red or blue) = 15
8. What is the probability of getting an odd number when rolling a single 6-sided die?
3
1
P(odd number) = 6 = 2
9. What is the probability of choosing a jack or a queen from a standard deck of 52 playing cards?
8
2
P(jack or queen) = 52 = 13
10. What is the probability of getting a 7 after rolling a single die numbered 1 to 6?
0
P(7) = 6
11. Bipasha loves purple, pink, turquoise and black, and has a blouse in each colour. She has two pairs of black
pants and a pair of khaki pants. If she randomly chooses one blouse and one pair of pants, what is the
probability she will wear a purple blouse with black pants?
Blouse
Pants
Outcomes
purple
Bl 1
Bl 2
K
PurpleBl1
PurpleBl2
PurpleK
pink
Bl 1
Bl 2
K
PinkBl1
PinkBl2
PinkK
turquoise
Bl 1
Bl 2
K
TurquoiseBl1
TurquoiseBl2
TurquoiseK
black
Bl 1
Bl 2
K
BlackBl1
BlackBl2
BlackK
2
1
P (purple blouse & black pants) = 12 = 6
12. Jay is looking in his closet, trying to decide what to wear. He has 2 red t-shirts, 2 black t-shirts, and 3 white tshirts. He has 3 pairs of blue jeans and 2 pairs of black pants.
T-Shirts
Pants
Outcomes
J1
Red1 J1
J2
Red1 J2
Red 1
J3
Red1 J3
BP 1
Red1 BP1
BP 2
Red1 BP2
Red 2
J1
J2
J3
BP 1
BP 2
Red2 J1
Red2 J2
Red2 J3
Red2 BP1
Red2 BP2
Black 1
J1
J2
J3
BP 1
BP 2
Black1 J1
Black1 J2
Black1 J3
Black1 BP1
Black1 BP2
Black 2
J1
J2
J3
BP 1
BP 2
Black2 J1
Black2 J2
Black2 J3
Black2 BP1
Black2 BP2
J1
J2
J3
BP 1
BP 2
White1 J1
White1 J2
White1 J3
White1 BP1
White1 BP2
J1
J2
J3
BP 1
BP 2
White2 J1
White2 J2
White2 J3
White2 BP1
White2 BP2
White 1
White 2
J1
White 3
J2
J3
BP 1
BP 2
a. What is the probability of his randomly choosing a red shirt with jeans?
6
P(red shirt with jeans) = 35
b. What is the probability of his randomly choosing an all-black outfit?
4
P (all black outfit) = 35
White3 J1
White3 J2
White3 J3
White 3 BP1
White3 BP2
c. Which combination out of all his possible choices has the greatest probability of being randomly
picked? How can you tell?
White t-shirt with jeans. More white t-shirts than any other colour and more jeans than black pants.
9
P (white t-shirt with jeans) = 35