Math (probability)

1. A bag contains 19 balls numbered 1 through 19. 

What is the probability of selecting a ball that has an even​ number?

		2/19
		9/19
		19/9
		9

5 points   

QUESTION 2

1. There are 3 balls in a​ hat; one with the number 3 on it, one with the number 4 on it, and one with the number 7 on it.

You pick a ball from the hat at random and then you flip a coin. Using a tree diagram​ , obtain the sample space for the experiment. List the elements that make up the sample space.

		3 H T, 4 H T 7H T
		3 4 7 H, 3 4 7 T
		3 H, 3 T, 4 H, 4 T, 7 H, 7 T
		3 H, 4 H, 7 H

5 points   

QUESTION 3

1.

What is the probability of drawing a club or a red card from a deck of 52 cards

		.75
		.25
		.50
		None of the above

5 points   

QUESTION 4

1. One person is selected at random from a class of 16 males and 15 females.  Find the odds against selecting:

a female

		15:16
		16:15
		15:31
		16:31

5 points   

QUESTION 5

1.

		6
		1/6
		3
		1/3

5 points   

QUESTION 6

1. A class consists of 24 women and 67 men. If a student is randomly​ selected, what is the probability that the student is a ​woman?

		1/91
		67/91
		24/67
		24/91

5 points   

QUESTION 7

1.

A couple plans to have three children.

Find the probability that the couple has a) no boys b) at least one girl, c) either exactly 2 girls or 2 boys. 

 

		a) 1/8  b) 1/8 c) 1/8
		a) 1/8 b) 7/8 c) 3/4
		a) 1/8  b) 1/2 c ) 3/4
		None of the above

5 points   

QUESTION 8

1.

Evaluate the expression:   8!

		40,320
		8
		56
		None of the above

5 points   

QUESTION 9

1.

On the lottery, where one number is chosen, determine the probability that you would win if you have a choice of 46 numbers to choose from

		45/46
		1/46
		1/2
		None of the above

5 points   

QUESTION 10

1.

Evaluate 8P3.

		336
		15
		56
		None of the above

5 points   

QUESTION 11

1.

A card is picked from a deck of cards. 

Find the odds against and the odds in favor of selecting a heart.

		3:1 , 1:3
		4:1 , 1:4
		1:3 , 3:1
		None of the above

5 points   

QUESTION 12

1. In a sample of 50,000 first-born babies, 5 were found to have Prader-Willi syndrome.

Find the emperical probability that the family's first child will be born with the syndrome .

		1/10000
		5/50000
		.0001
		All of the above

5 points   

QUESTION 13

1.

A traffic light is red for 25 seconds, yellow for 5 seconds, and green for 55 seconds. 

What is the probability that when you reach the light - the light is yellow?

		5/85 + 80/85
		5/85 or 1/17
		80/85 or 16/17
		None of the above

5 points   

QUESTION 14

1.

 Jim finds an irregularly shaped five-sided rock.  He labels each side and tossed the rock 100 times. The results are in the following table.

Side            1     2    3     4      5  

Frequency   32    18  15  13     22

Find the emperical probability that the rock will land on side 4 if tossed again.

		13/100
		4/13
		4/100
		None of the above

5 points   

QUESTION 15

1. A number labeled with numbers 1, 2, 3, 4, 5, and 6 is tossed.  What are the odds in favor of the cube showing a number less than 3?

		1:2
		1:3
		1:1
		2:1

5 points   

QUESTION 16

1.

		3/4
		4/5
		5/4
		1/4

5 points   

QUESTION 17

1.

Evaluate 10C3.

		360
		120
		720
		none of the above

5 points   

QUESTION 18

1. A contractor is considering a sale that promises a profit of $40,000 with a probability of 0.7 or a loss of $5,000 with a probability of 0.3.  What is the expected profit?

		$31,500
		$28,000
		$26,500
		$35,000

5 points   

QUESTION 19

1.

In July in Seattle, the grass grows 1/2 inch a day on a sunny day and 1/4 inch a day on a cloudy day. In Seattle, in July, 75% of the days are sunny and 25% of the days are cloudy.

a) Find the expected value of grass growth for the day  b) Find the expected value of grass growth for the month of July ( 31 days ) -- round both to 2 decimal placees

		a) .50 in  b)  15.5 in
		a) .75  in  b) 23.23 in
		a) .44 in  b) 13.64 in
		None of the above

5 points   

QUESTION 20

1. One digit from the number 5, 494, 224 is written on each of seven cards. What is the probability of drawing a card that shows 5 or 2?

		5/7
		4/7
		3/7
		2/7

5 points