Biased and Unbiased Samples

A bag contains 5 red, 3 blue, and 2 green marbles. What is the probability of picking a red marble from the bag?

• 2/5

• 5/10 or 1/2 or 0.5

• 3/10

• 0.3

Tags

CCSS.7.SP.C.7B

In a class of 30 students, 18 are girls and 12 are boys. If a student is chosen at random, what is the probability of selecting a girl?

• 5/12

• 3/5

• 2/5

• 1/3

Tags

CCSS.7.SP.C.7B

A box contains 4 black socks, 3 white socks, and 2 blue socks. What is the probability of picking a white sock from the box?

• 3/9 or 1/3

• 1/2

• 4/9

• 2/9

Tags

CCSS.7.SP.C.7B

In a survey, 60% of people prefer tea over coffee. If 200 people are surveyed, how many are expected to prefer tea?

• 120

• 150

• 100

• 80

Tags

CCSS.7.SP.A.2

A jar contains 10 red balls and 5 blue balls. If 2 balls are drawn at random, what is the probability of getting 1 red and 1 blue ball?

• 2/15

• 3/14

• 10/21

• 5/21

Tags

CCSS.HSS.CP.B.9

In a group of 50 students, 30 play football and 20 play basketball. If a student is chosen at random, what is the probability of selecting a basketball player?

• 0.4 or 40%

• 0.5 or 50%

• 0.3 or 30%

• 0.6 or 60%

Tags

CCSS.7.SP.C.7B

A bag contains 6 green, 4 yellow, and 5 red candies. What is the probability of picking a yellow candy from the bag?

• 3/15 or 0.2

• 4/15 or 0.2667

• 2/15 or 0.1333

• 5/15 or 0.3333

Tags

CCSS.7.SP.C.7B

In a survey, 40% of people prefer dogs as pets. If 150 people are surveyed, how many are expected to prefer dogs?

• 90

• 60

• 30

• 120

Tags

CCSS.7.SP.C.6

A box contains 8 black pens, 6 blue pens, and 4 red pens. What is the probability of picking a red pen from the box?

• 4/18 or 2/9

• 4/6 or 2/3

• 4/10 or 2/5

• 4/8 or 1/2

Tags

CCSS.7.SP.C.7B

In a group of 80 students, 50 like to read and 30 like to draw. If a student is chosen at random, what is the probability of selecting a student who likes to draw?

• 0.625

• 0.375

• 0.45

• 0.25

Tags

CCSS.7.SP.C.7B