# Sets

## Overview

Sets are foundational concepts in mathematics that play a crucial role in categorizing and organizing elements based on their characteristics or properties. In the realm of General Mathematics, understanding sets is fundamental for problem-solving and reasoning.

One of the primary objectives when delving into the topic of sets is to identify the various types of sets that exist. These include empty sets, which contain no elements; universal sets, which encompass all possible elements under consideration; complements, denoting elements not included in a specific set; subsets, where all elements of one set are contained within another; finite sets with a distinct number of elements; infinite sets with an endless number of elements; and disjoint sets, which do not share any common elements.

Furthermore, mastery of sets involves being able to solve problems concerning the cardinality of sets. The cardinality of a set simply refers to the number of elements it contains. By understanding how to determine the cardinality of sets, mathematicians can make informed decisions and draw logical conclusions based on the data provided.

Symbolic representation is another crucial aspect of working with sets. Solving set problems using symbols allows for a concise and systematic approach to understanding relationships between different sets. Symbols such as ∪ (union), ∩ (intersection), and ' (complement) are commonly employed to denote set operations and relationships.

Moreover, the application of Venn diagrams is integral to solving problems involving sets, particularly when dealing with not more than three sets. Venn diagrams provide a visual representation of the relationships between sets, making it easier to analyze overlapping and distinct elements. By utilizing Venn diagrams, mathematicians can effectively visualize set operations and make informed deductions based on the information presented.

## Objectives

1. Identify Types of Sets
2. Use Venn Diagrams to Solve Problems Involving not more than 3 Sets
3. Solve Set Problems Using Symbols
4. Solve Problems Involving Cardinality of Sets

## Lesson Note

In mathematics, a set is a collection of distinct objects, considered as an object in its own right. For example, the numbers 2, 4, and 6 are distinct objects when considered separately, but when they are considered collectively as the set {2, 4, 6}, they form a single object. Sets are fundamental objects in mathematics.

## Lesson Evaluation

Congratulations on completing the lesson on Sets. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

1. What are the three basic types of sets based on their elements? A. Universal, Infinite, Finite B. Empty, Universal, Complements C. Finite, Infinite, Complements D. Equal, Subsets, Venn Diagrams Answer: B. Empty, Universal, Complements
2. If set A = {1, 2, 3} and set B = {3, 4, 5}, what is A ∩ B? A. {1, 2, 3} B. {3} C. {4, 5} D. {1, 2, 3, 4, 5} Answer: B. {3}
3. If set C = {6, 7, 8, 9} and set D = {8, 9, 10}, what is C ∪ D? A. {6, 7, 8, 9} B. {8, 9} C. {6, 7, 8, 9, 10} D. {6, 7, 10} Answer: C. {6, 7, 8, 9, 10}
4. What is the cardinality of the set E = {apple, banana, apple, orange}? A. 4 B. 3 C. 2 D. 1 Answer: B. 3
5. If set F = {x
6. x < 5}, and set G = {x
7. x > 2}, what is F ∩ G? A. {2, 5} B. {3, 4} C. {2, 3, 4} D. {1, 2, 3, 4, 5} Answer: B. {3, 4}
8. What is the complement of a set H = {a, b, c}? A. {a, b, c} B. { } C. Universal set D. {d, e, f} Answer: D. {d, e, f}
9. If set I = {1, 2, 3} and set J = {4, 5, 6}, what is the Cartesian product of I × J? A. {(1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6)} B. {(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)} C. {(1, 4), (2, 5), (3, 6)} D. {(1, 4, 2), (3, 5, 6)} Answer: A. {(1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6)}
10. In a survey, 50 people like only tea, 30 people like only coffee, and 20 people like both. How many people were surveyed in total? A. 50 B. 80 C. 100 D. 120 Answer: C. 100
11. What is the Venn diagram representation of two disjoint sets? A. Two circles intersecting B. Two circles completely separate C. Two circles partially overlapping D. A single circle Answer: B. Two circles completely separate

## Past Questions

Wondering what past questions for this topic looks like? Here are a number of questions about Sets from previous years

Question 1

The table gives the distribution of outcomes obtained when a die was rolled 100 times.

What is the experimental probability that it shows at most 4 when rolled again?

Question 1

If A = { 1, 2, 3, 4, 5, 6}, B = { 2, 4, 6, 8 }. Find (A – B) ⋃ (B – A).

Question 1

If n{A} = 6, n{B} = 5 and n{A ∩ B} = 2, find n{A ∪ B}

Practice a number of Sets past questions