PROBABILITY

​PROBABILITY QUIZ

Multiple Choice

What is the probability of getting 6 when you roll a regular dice?

• unlikely 

• impossible

• likely

• certain

unlikely

​There is only one number 6 in a regular die. There is a total of 6 possible outcomes. 1,2,3,4,5,and 6

​thus:

​P/E = 1/6

​0.1666

​17%

Multiple Choice

Consider picking a card from a standard deck of 52 cards. What is the probability of getting a diamond?

• impossible

• likely

• as likely, as unlikely

• unlikely

unlikely

There are 13 diamond cards in a standard deck of 52 cards. Hence,

​

​P/E = 13/52 = 1/4

0.25

​25%

Multiple Choice

Consider picking a card of a standard deck of 52 cards. What is the probability of getting a king?

• 1/13

• 1/2 

• 1/52

• 1/4

1/13

There are 4 kings in a standard deck of 52 cards. Therefore,

​

​P/E = 4/52

= 1/13

​

Multiple Choice

Suppose each letter of the word compute is written on a card and placed in a box. What is the probability of picking a card containing a consonant?

• 57% 

• 43%

• 100%

• 14%

57%

COMPUTE has 7 letters, There are 4 consonants (C, M, P and T). Thus,

​

​P/E = 4/7

= 57%

​

Multiple Choice

In a bowl, there are 5 green marbles, 4 red marbles, and 7 blue marbles. What is the probability of getting a red marble?

• impossible

• unlikely

• likely

• certain

unlikely

There are 16 total marbles, four of them are red. Thus, the probability of getting a red marble is

​

​P/E = 4/16

= 1/4 or 25%

​

Multiple Choice

Consider picking a number from 1 to 15? What is the probability of getting a composite number?

• 8/15 

• 7/15

• 1/2

• 2/3

8/15

There are 8 composite numbers from 1 to 15, (4,6,8,9,10,12,14,15). Thus,

​

​P/E = 8/15

​

Multiple Choice

Consider picking a number from all even numbers from 1-15. What is the probability of picking a prime number?

• 1/7

• 2/7

• 4/7

• 6/7

1/7

There are 7 numbers from 1 - 15, (2,4,6,8,10,12,14). There is only one even prime number (2). Thus,

​P/E = 1/7

​

Multiple Choice

Consider picking a letter from the English alphabet. What is the probability of picking a consonant?

• 81%

• 73%

• 65%

• 88%

81%

There is a total of 26 letters in the English alphabet. Only 21 of these are consonants. Therefore,

​P/E = 21/26

=0.807​

= 81%​

​

​

Multiple Choice

A student is asked to get a marble from a bag without looking. The bag contains seven black marbles, five white marbles, and three blue marbles. What is the probability that the student will get a blue marble?

• as unlikely, as likely

• likely

• unlikely

• certain

unlikely

The bag contains a total of 15 marbles. There are 3 blue marbles, hence,

​P/E = 3/15

= 20

= 20%​

​

​

Multiple Choice

Five boys and four girls signed up for a chess tournament. Shirley is among those who signed up. If the players are randomly paired off, what is the probability that Shirley’s opponent is a boy?

• 0.62

• 0.37

• 0.50

• 0.75

0.62

The total number of opponents is eight, Of these, five are boys. Thus,

​P/E = 5/8

= 0.62

= 62%​

​

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