Sets and Probability

A bag contains 5 red marbles, 4 blue marbles and a green marble. Two marbles are drawn from the bag (without replacement). What is the probability that both marbles are red?

• ⅕ × ¼ = 1/20

• 4/5 × 4/5 = 16/25

• 4/5 × 3/4 = 12/20

• none of these options is correct

A bag contains 5 red marbles, 4 blue marbles and a green marble. Two marbles are drawn from the bag (without replacement). What is the probability that both the second marble is green, given that the first marble was red?

• 1/9

• 1/20

• 2/20

• none of these options is correct

Set  Q  contains the letters in the word  SISTER .
 Which of the following is set  Q ?

• Q = { S, T, R }

• Q = { I, E }

• Q = { S, I, S, T, E, R }

• Q = { S, I, T, E, R }

If every element in set A is also in set B, then...

• A is a subset of B

• B is a subset of A

• A = B

• A and B are disjoint

What is #A?

• 9

• {1,3,5,9}

• 5

• 4

If A = {1, 3, 5, 7, 9} and B = {2, 3, 5, 7}, what is A ∪ B?

• {3, 5, 7}

• {2, 3, 5, 7}

• {2, 3, 5, 7, 9}

• {1, 2, 3, 5, 7, 9}

If A = {1, 3, 5, 7, 9} and B = {2, 3, 5, 7}, what is A ∩ B?

• {3, 5, 7}

• {2, 3, 5, 7}

• {2, 3, 5, 7, 9}

• {1, 2, 3, 5, 7, 9}

The Universal Set = { -4, 3, -2, -1, 0, 1, 2, 3 ,4} and A = {0}.
What is the complement of A?

• {-4, -3, -2, -1, 0, 1, 2, 3}

• {-3, -2, -1, 1, 2, 3}

• {-4, -3, -2, -1, 1, 2, 3, 4}

• {-4, -3, -2, -1, 1, 2, 3}

What is the probability of choosing the letter
i from the word probability?

• 1/10

• 2/11

• 2/2

• 1/10

What is the highlighted region

• A⋂B

• AUB

• A⊆B

• A∄B