Sets and functions

If A = {1, 2, 3} and B = {3, 4}, what is A union B?

• 1 {3}
• 2 {4}
• 3 {1, 2, 4}
• 4 {1, 2, 3, 4}

If A = {1, 2, 3} and B = {3, 4}, what is A intersection B?

• 1 {3}
• 2 empty set
• 3 {1, 2, 3, 4}
• 4 {1, 2}

The number of subsets of a set with 3 elements is:

• 1 6
• 2 8
• 3 3
• 4 9

If f(x) = 2x + 3, what is f(4)?

• 1 8
• 2 14
• 3 11
• 4 7

A relation in which every input has exactly one output is a:

• 1 Function
• 2 Set
• 3 Matrix
• 4 Ratio

If A has 4 elements and B has 3 elements, how many elements are in A x B?

• 1 12
• 2 81
• 3 7
• 4 1

The empty set is written as:

• 1 { }
• 2 {0}
• 3 [ ]
• 4 {1}

If A = {1, 2} and B = {2, 3}, the set A - B is:

• 1 {1, 2}
• 2 {2}
• 3 {3}
• 4 {1}

The domain of the function f = {(1, 2), (3, 4)} is:

• 1 {1, 2, 3, 4}
• 2 {4}
• 3 {2, 4}
• 4 {1, 3}

A set with exactly one element is called a:

• 1 Singleton
• 2 Power set
• 3 Universal set
• 4 Empty set