Understanding Sets and Notation

What is a set?

• A random collection of objects

• A well-defined group of objects

• A group of mixed items with no specific criteria

• Any collection of numbers only

What is the correct term for the objects in a set?

• Factors

• Components

• Elements

• Variables

Which of the following sets is not well-defined?

• The set of prime numbers less than 10

• The set of vowels in the English alphabet

• The set of beautiful flowers

• The set of primary colors

What symbol is used to represent that an element belongs to a set?

• ∉

• ∩

• ⊆

• ∈

Which of the following best describes a well-defined set?

• A collection of items that have a clear membership rule

• A random list of items

• A collection of numbers only

• A group of objects chosen by preference

If A = {2, 4, 6, 8}, which of the following is true?

• 3 ∈ A

• 6 ∈ A

• 9 ∈ A

• 10 ∈ A

Which of the following sets is represented correctly using the Roster Method?

• A = { x | x is an even number }

• B = {a, e, i, o, u}

• C = { x | x is a natural number less than 5 }

• D = { x | x is a city in the Philippines }

Convert the verbal description into the Roster Method: "The set of months in a year that start with J."

• {June, July, January}

• {January, July, June}

• {January, June, July, September}

• {June, July, August}

If B = {x | x is a multiple of 3, x < 10}, what is the roster notation of B?

• {3, 6, 9}

• {1, 2, 3}

• {3, 6, 9, 12}

• {0, 3, 6, 9, 12}

Identify the correct Set-Builder Notation for the set A = {1, 3, 5, 7, 9}.

• A = {x | x is an even number}

• A = {x | x is an odd number less than 10}

• A = {x | x is a prime number less than 10}

• A = {x | x is a whole number}