Probability. Flashcards
State whether each situation describes an ordered or unordered selection.
A) Betting on the Melbourne Cup Trifecta (the first three places).
B) The letters and numbers on a car number plate.
C) Selecting a volleyball team form 14 players.
D) Using a 6-digit code to open a suitcase.
E) Selecting a hand of 7 cards from a deck of 52 cards.
F) Choosing 3 friends to go a concert with you.
G) Choosing a sample of 20 light globes to test.
A) Ordered B) Ordered C) Unordered D) Ordered E) Unordered F) Unordered G) Unordered
In an election, five candidates are listed at random on a ballot (voting) paper.
A) How many ways are there of listing the five candidates?
B) What is the probability that the candidates are listed in alphabetical order?
C) If Ms Ward is listed first, how many ways are there of listing the other four candidates?
A) 120
B) 1/120
C) 24
A bag contains 6 red marbles and 4 blue marbles. Four marbles are drawn from the bag.
A) How many different selections are possible?
B) How many different ways are there of selecting 4 red marbles from 6 red marbles?
C) What is the probability of selecting 4 red marbles from the bag?
A) 210
B) 15
C) 1/14
From a group of 7 authors, three are selected to write a book. What is the probability the Klaas, David and Colin are selected?
1/35
A) How many 4-letter arrangements can be made form the word computer?
B) What is the probability that an arrangement selected at random begins with the letter P?
A) 1680
B) 1/8
The probability of a new globe not working is 0.036. If 5821 light globes are produced by a factory in one day, how many of them can be expected not to be working?
210
On a TV game show, a contestant selects one of 9 panels which is turned around to reveal a prize. The panels contain 3 cash prizes, 2 holidays, 1 car and three other prizes. How often should a holiday be won over 260 shows?
A) 29
B) 47
C) 58
D) 65
C
One card is randomly selected from a normal deck of playing cards. If this experiment is performed 40 times, how many times should:
A) A queen be selected?
B) A club be selected?
C) An odd-numbered card be selected?
A) 3
B) 10
C) 12
A pair of coins is tossed 300 times. How often would you expect 2 heads to come up?
75
Jeff tosses two coins and wins $2 for 2 heads, $1 for 2 tails and nothing otherwise. Calculate his financial expectation.
$0.75
You are given two options:
A) A 100% chance of receiving $200 each week.
B) A 70% chance of receiving $500 and a 30% chance of losing $200 each week.
In the long run, which is the better option? Justify your answer.
B, with a financial expectation of $290.
