8-4: Union & Intersection

Suppose A={factors of 20} and B={factors of 12}, what is  $A\cap B$  ?

• {1, 2, 4}

• {1, 2, 3, 4, 5, 6, 10, 12, 20}

• {12, 20}

• {3, 5, 6, 10, 12, 20}

Let Set A be all of the girls in the classroom. Let Set B be all of the sophomores in the classroom. What is the complement of Set A?

• The freshman, the juniors, and the seniors

• The boys in the classroom

• The girls who are not sophomores

• The sophomores who are not girls

Suppose Set A = {5, 10, 15, 20, 25, 30} and Set B = {10, 20, 30, 40, 50, 60}. What is  $A\cup B$  ?

• {10, 20, 30}

• {5, 15, 25, 40, 50, 60}

• {5, 10, 15, 20, 25, 30, 40, 50, 60}

• No Solution

Use the numbers 1 through 20 as a sample space for the sets described below.

X = {multiples of 3}

Y = {multiples of 4}

Z = {factors of 12}

Which statement is true?

• The intersection of X and Z is {3,6,12}

• The union of Y and Z is {4}

• The union of X and Y is {12}

• The intersection of X, Y, and Z is {1,2,3,4,6,8,9,12,15,16,18,20}

 Suppose Set A = {Factors of 24} and Set B = {Factors of 36}. What is  $A\cap B$  ?

• {24, 36}

• {1, 2, 3, 4, 6, 8, 9, 12}

• {8, 9, 18, 24, 36}

• {1, 2, 3, 4, 6, 12}

Suppose A = {black, white, silver, gold}, M = {Silver, white, green}, and R = {green, white, blue}. Which set is equivalent to  $\left(A\cup M\right)\cap R$  ?

• {green, white}

• {silver, white}

• {silver, white, green, blue}

• {blue}

Three sets are defined as follows.
W: {even integers}
X: {multiples of 3}
Z: $\left\{W\cap X\right\}$  
Which choice is an element of Z?

• -9

• -8

• -7

• -6

Suppose Set A = {2, 4, 6, 8, 10, 12} and Set B = {4, 5, 6, 7, 8, 9}. What is  $A\cup B$  ?

• {4, 6, 8}

• {2, 4, 5, 6, 7, 8, 9, 10, 12}

• {2, 7, 9, 10, 12}

• No Solution

Suppose A = {red, blue, yellow}, B = {Red, yellow, green}, and C = {green, red, purple}. Which set is equivalent to  $\left(A\cup B\right)\cap C$ ?

• {purple}

• {red}

• {red, green}

• {yellow, purple}

Use the numbers 1 through 20 as a sample space for the sets of numbers described below.

X = {multiples of 4}

Y = {multiples of 5}

Z = {factors of 10}

Which statement is true?

• The intersection of Y and Z is no solution

• The intersection of Y and Z is {1,2,5,10,15,20}

• The union of X and Y is {20}

• The union of X, Y, and Z is {1,2,4,5,8,10,12,15,16,20}