By the end of this chapter, you will be able to:
Mastering these skills will help you think clearly and solve problems efficiently in many technical and practical jobs.
Discrete mathematical concepts form the foundational language for many ICT operations, including database management, network design, and algorithm development. Set theory, in particular, provides a structured way to handle collections of distinct objects such as IP addresses, user groups, and data packets. Mastering set operations enables ICT technicians to efficiently organize, query, and manipulate data sets critical to system administration and software configuration in Kenyan ICT environments.
In ICT, sets are used to represent groups of data elements such as user permissions, device lists, or network nodes. Accurately representing these sets and understanding their properties ensure correct data handling and system integrity. This section covers how sets are defined, their fundamental properties, and common methods of representation relevant to ICT tasks.
Set theory operations allow manipulation and combination of data collections, essential for tasks like filtering user access or merging device inventories. The primary operations are union, intersection, difference, and complement. Each operation follows specific rules that affect the resulting data set.
$$ A \cup B = \{ x \mid x \in A \text{ or } x \in B \} $$
$$ A \cap B = \{ x \mid x \in A \text{ and } x \in B \} $$
$$ A - B = \{ x \mid x \in A \text{ and } x otin B \} $$
$$ A^{c} = \{ x \mid x otin A \} $$
Example 1: A bank's ICT department has set \(A\) of authorized users for the finance system: \(A = \{ \text{Alice}, \text{Bob}, \text{Charles} \}\) and set \(B\) of users authorized for the HR system: \(B = \{ \text{Bob}, \text{Diana} \}\). Find \(A \cup B\).
Given:
\(A = \{ \text{Alice}, \text{Bob}, \text{Charles} \}\)
\(B = \{ \text{Bob}, \text{Diana} \}\)
$$ A \cup B = \{ x \mid x \in A \text{ or } x \in B \} $$
$$ A \cup B = \{ \text{Alice}, \text{Bob}, \text{Charles}, \text{Diana} \} $$
Answer: \( \{ \text{Alice}, \text{Bob}, \text{Charles}, \text{Diana} \} \)
Example 2: Using the same sets, find \(A \cap B\).
Given:
\(A = \{ \text{Alice}, \text{Bob}, \text{Charles} \}\)
\(B = \{ \text{Bob}, \text{Diana} \}\)
$$ A \cap B = \{ x \mid x \in A \text{ and } x \in B \} $$
$$ A \cap B = \{ \text{Bob} \} $$
Answer: \( \{ \text{Bob} \} \)
Example 3: Find \(A - B\), users authorized only for the finance system.
Given:
\(A = \{ \text{Alice}, \text{Bob}, \text{Charles} \}\)
\(B = \{ \text{Bob}, \text{Diana} \}\)
$$ A - B = \{ x \mid x \in A \text{ and } x otin B \} $$
$$ A - B = \{ \text{Alice}, \text{Charles} \} $$
Answer: \( \{ \text{Alice}, \text{Charles} \} \)
Example 4: If the universal set \(U = \{ \text{Alice}, \text{Bob}, \text{Charles}, \text{Diana}, \text{Edward} \}\), find \(A^c\).
Given:
\(U = \{ \text{Alice}, \text{Bob}, \text{Charles}, \text{Diana}, \text{Edward} \}\)
\(A = \{ \text{Alice}, \text{Bob}, \text{Charles} \}\)
$$ A^{c} = \{ x \mid x otin A \} $$
$$ A^{c} = \{ \text{Diana}, \text{Edward} \} $$
Answer: \( \{ \text{Diana}, \text{Edward} \} \)
Example 5: In a network, set \(X = \{ 192.168.1.1, 192.168.1.2, 192.168.1.3 \}\) represents active devices, set \(Y = \{ 192.168.1.2, 192.168.1.4 \}\) represents devices under maintenance. Find \(X \cup Y\).
Given:
\(X = \{ 192.168.1.1, 192.168.1.2, 192.168.1.3 \}\)
\(Y = \{ 192.168.1.2, 192.168.1.4 \}\)
$$ X \cup Y = \{ x \mid x \in X \text{ or } x \in Y \} $$
$$ X \cup Y = \{ 192.168.1.1, 192.168.1.2, 192.168.1.3, 192.168.1.4 \} $$
Answer: \( \{ 192.168.1.1, 192.168.1.2, 192.168.1.3, 192.168.1.4 \} \)
Sets have properties that govern their behaviour during operations. Recognizing these properties ensures correct application of set operations in ICT tasks such as database querying and security filtering.
The order of operands in union or intersection does not affect the result.
$$ A \cup B = B \cup A $$
$$ A \cap B = B \cap A $$
Example 1: Confirm commutativity for sets \(A = \{1,2,3\}\) and \(B = \{3,4\}\) with union.
Given:
\(A = \{1,2,3\}\)
\(B = \{3,4\}\)
$$ A \cup B = \{1,2,3,4\} $$
$$ B \cup A = \{3,4,1,2\} = \{1,2,3,4\} $$
Answer: \(A \cup B = B \cup A = \{1,2,3,4\}\)
Example 2: Confirm commutativity for intersection with same sets.
Given:
\(A = \{1,2,3\}\)
\(B = \{3,4\}\)
$$ A \cap B = \{3\} $$
$$ B \cap A = \{3\} $$
Answer: \(A \cap B = B \cap A = \{3\}\)
Example 3: Verify commutativity for sets of device IDs \(C = \{D01, D02\}\), \(D = \{D02, D03\}\).
Given:
\(C = \{D01, D02\}\)
\(D = \{D02, D03\}\)
$$ C \cup D = \{D01, D02, D03\} $$
$$ D \cup C = \{D02, D03, D01\} = \{D01, D02, D03\} $$
Answer: \(C \cup D = D \cup C = \{D01, D02, D03\}\)
Example 4: Confirm commutativity for intersection of same sets.
Given:
\(C = \{D01, D02\}\)
\(D = \{D02, D03\}\)
$$ C \cap D = \{D02\} $$
$$ D \cap C = \{D02\} $$
Answer: \(C \cap D = D \cap C = \{D02\}\)
Example 5: Check commutativity for union with data user groups \(E = \{\text{Admin}, \text{User}\}\), \(F = \{\text{User}, \text{Guest}\}\).
Given:
\(E = \{\text{Admin}, \text{User}\}\)
\(F = \{\text{User}, \text{Guest}\}\)
$$ E \cup F = \{\text{Admin}, \text{User}, \text{Guest}\} $$
$$ F \cup E = \{\text{User}, \text{Guest}, \text{Admin}\} = \{\text{Admin}, \text{User}, \text{Guest}\} $$
Answer: \(E \cup F = F \cup E = \{\text{Admin}, \text{User}, \text{Guest}\}\)
Grouping of sets in union or intersection does not affect the result.
$$ (A \cup B) \cup C = A \cup (B \cup C) $$
$$ (A \cap B) \cap C = A \cap (B \cap C) $$
Example 1: Given \(A = \{1,2\}\), \(B = \{2,3\}\), \(C = \{3,4\}\), verify associative property for union.
Given:
\(A = \{1,2\}\)
\(B = \{2,3\}\)
\(C = \{3,4\}\)
$$ (A \cup B) \cup C = \{1,2,3\} \cup \{3,4\} = \{1,2,3,4\} $$
$$ A \cup (B \cup C) = \{1,2\} \cup \{2,3,4\} = \{1,2,3,4\} $$
Answer: \(\{1,2,3,4\} = \{1,2,3,4\}\)
Example 2: Verify associative property for intersection with same sets.
Given:
\(A = \{1,2,3\}\)
\(B = \{2,3,4\}\)
\(C = \{3,4,5\}\)
$$ (A \cap B) \cap C = \{2,3\} \cap \{3,4,5\} = \{3\} $$
$$ A \cap (B \cap C) = \{1,2,3\} \cap \{3,4\} = \{3\} $$
Answer: \(\{3\} = \{3\}\)
Example 3: Confirm associative union property for network devices \(X = \{D1, D2\}\), \(Y = \{D2, D3\}\), \(Z = \{D3, D4\}\).
Given:
\(X = \{D1, D2\}\)
\(Y = \{D2, D3\}\)
\(Z = \{D3, D4\}\)
$$ (X \cup Y) \cup Z = \{D1, D2, D3\} \cup \{D3, D4\} = \{D1, D2, D3, D4\} $$
$$ X \cup (Y \cup Z) = \{D1, D2\} \cup \{D2, D3, D4\} = \{D1, D2, D3, D4\} $$
Answer: \(\{D1, D2, D3, D4\} = \{D1, D2, D3, D4\}\)
Example 4: Verify associative intersection property for user groups \(E = \{\text{Admin}, \text{User}\}\), \(F = \{\text{User}, \text{Guest}\}\), \(G = \{\text{User}, \text{Auditor}\}\).
Given:
\(E = \{\text{Admin}, \text{User}\}\)
\(F = \{\text{User}, \text{Guest}\}\)
\(G = \{\text{User}, \text{Auditor}\}\)
$$ (E \cap F) \cap G = \{\text{User}\} \cap \{\text{User}, \text{Auditor}\} = \{\text{User}\} $$
$$ E \cap (F \cap G) = \{\text{Admin}, \text{User}\} \cap \{\text{User}\} = \{\text{User}\} $$
Answer: \(\{\text{User}\} = \{\text{User}\}\)
Example 5: Check associative union property for IP address sets \(P = \{10.0.0.1, 10.0.0.2\}\), \(Q = \{10.0.0.2, 10.0.0.3\}\), \(R = \{10.0.0.3, 10.0.0.4\}\).
Given:
\(P = \{10.0.0.1, 10.0.0.2\}\)
\(Q = \{10.0.0.2, 10.0.0.3\}\)
\(R = \{10.0.0.3, 10.0.0.4\}\)
$$ (P \cup Q) \cup R = \{10.0.0.1, 10.0.0.2, 10.0.0.3\} \cup \{10.0.0.3, 10.0.0.4\} = \{10.0.0.1, 10.0.0.2, 10.0.0.3, 10.0.0.4\} $$
$$ P \cup (Q \cup R) = \{10.0.0.1, 10.0.0.2\} \cup \{10.0.0.2, 10.0.0.3, 10.0.0.4\} = \{10.0.0.1, 10.0.0.2, 10.0.0.3, 10.0.0.4\} $$
Answer: \(\{10.0.0.1, 10.0.0.2, 10.0.0.3, 10.0.0.4\} = \{10.0.0.1, 10.0.0.2, 10.0.0.3, 10.0.0.4\}\)
Union and intersection distribute over each other:
$$ A \cup (B \cap C) = (A \cup B) \cap (A \cup C) $$
$$ A \cap (B \cup C) = (A \cap B) \cup (A \cap C) $$
Example 1: Given \(A = \{1,2,3\}\), \(B = \{2,3,4\}\), \(C = \{3,4,5\}\), verify distributive property for union over intersection.
Given:
\(A = \{1,2,3\}\)
\(B = \{2,3,4\}\)
\(C = \{3,4,5\}\)
$$ B \cap C = \{3,4\} $$
$$ A \cup (B \cap C) = \{1,2,3\} \cup \{3,4\} = \{1,2,3,4\} $$
$$ A \cup B = \{1,2,3,4\} $$
$$ A \cup C = \{1,2,3,4,5\} $$
$$ (A \cup B) \cap (A \cup C) = \{1,2,3,4\} \cap \{1,2,3,4,5\} = \{1,2,3,4\} $$
Answer: \(\{1,2,3,4\} = \{1,2,3,4\}\)
Example 2: Verify distributive property for intersection over union with same sets.
Given:
\(A = \{1,2,3\}\)
\(B = \{2,3,4\}\)
\(C = \{3,4,5\}\)
$$ B \cup C = \{2,3,4,5\} $$
$$ A \cap (B \cup C) = \{1,2,3\} \cap \{2,3,4,5\} = \{2,3\} $$
$$ A \cap B = \{2,3\} $$
$$ A \cap C = \{3\} $$
$$ (A \cap B) \cup (A \cap C) = \{2,3\} \cup \{3\} = \{2,3\} $$
Answer: \(\{2,3\} = \{2,3\}\)
Example 3: In a school ICT system, \(X = \{\text{Math}, \text{Physics}\}\), \(Y = \{\text{Physics}, \text{Chemistry}\}\), \(Z = \{\text{Chemistry}, \text{Biology}\}\). Verify distributive union over intersection.
Given:
\(X = \{\text{Math}, \text{Physics}\}\)
\(Y = \{\text{Physics}, \text{Chemistry}\}\)
\(Z = \{\text{Chemistry}, \text{Biology}\}\)
$$ Y \cap Z = \{\text{Chemistry}\} $$
$$ X \cup (Y \cap Z) = \{\text{Math}, \text{Physics}\} \cup \{\text{Chemistry}\} = \{\text{Math}, \text{Physics}, \text{Chemistry}\} $$
$$ X \cup Y = \{\text{Math}, \text{Physics}, \text{Chemistry}\} $$
$$ X \cup Z = \{\text{Math}, \text{Physics}, \text{Chemistry}, \text{Biology}\} $$
$$ (X \cup Y) \cap (X \cup Z) = \{\text{Math}, \text{Physics}, \text{Chemistry}\} \cap \{\text{Math}, \text{Physics}, \text{Chemistry}, \text{Biology}\} = \{\text{Math}, \text{Physics}, \text{Chemistry}\} $$
Answer: \(\{\text{Math}, \text{Physics}, \text{Chemistry}\} = \{\text{Math}, \text{Physics}, \text{Chemistry}\}\)
Example 4: Verify distributive intersection over union with same sets.
Given:
\(X = \{\text{Math}, \text{Physics}\}\)
\(Y = \{\text{Physics}, \text{Chemistry}\}\)
\(Z = \{\text{Chemistry}, \text{Biology}\}\)
$$ Y \cup Z = \{\text{Physics}, \text{Chemistry}, \text{Biology}\} $$
$$ X \cap (Y \cup Z) = \{\text{Math}, \text{Physics}\} \cap \{\text{Physics}, \text{Chemistry}, \text{Biology}\} = \{\text{Physics}\} $$
$$ X \cap Y = \{\text{Physics}\} $$
$$ X \cap Z = \{\} $$
$$ (X \cap Y) \cup (X \cap Z) = \{\text{Physics}\} \cup \{\} = \{\text{Physics}\} $$
Answer: \(\{\text{Physics}\} = \{\text{Physics}\}\)
Example 5: In a retail SACCO, \(A = \{\text{Loan}, \text{Savings}\}\), \(B = \{\text{Savings}, \text{Investment}\}\), \(C = \{\text{Investment}, \text{Insurance}\}\). Verify distributive union over intersection.
Given:
\(A = \{\text{Loan}, \text{Savings}\}\)
\(B = \{\text{Savings}, \text{Investment}\}\)
\(C = \{\text{Investment}, \text{Insurance}\}\)
$$ B \cap C = \{\text{Investment}\} $$
$$ A \cup (B \cap C) = \{\text{Loan}, \text{Savings}\} \cup \{\text{Investment}\} = \{\text{Loan}, \text{Savings}, \text{Investment}\} $$
$$ A \cup B = \{\text{Loan}, \text{Savings}, \text{Investment}\} $$
$$ A \cup C = \{\text{Loan}, \text{Savings}, \text{Investment}, \text{Insurance}\} $$
$$ (A \cup B) \cap (A \cup C) = \{\text{Loan}, \text{Savings}, \text{Investment}\} \cap \{\text{Loan}, \text{Savings}, \text{Investment}, \text{Insurance}\} = \{\text{Loan}, \text{Savings}, \text{Investment}\} $$
Answer: \(\{\text{Loan}, \text{Savings}, \text{Investment}\} = \{\text{Loan}, \text{Savings}, \text{Investment}\}\)
Sets are collections of distinct elements where the order does not matter. This distinguishes sets from lists or arrays, which are ordered and may contain duplicates. Understanding this is critical when dealing with data structures in ICT systems.
The order of elements in a set is immaterial; the set \(\{a, b, c\}\) is identical to \(\{c, a, b\}\).
Example 1: Confirm if \(A = \{ \text{User1}, \text{User2} \}\) equals \(B = \{ \text{User2}, \text{User1} \}\).
Given:
\(A = \{ \text{User1}, \text{User2} \}\)
\(B = \{ \text{User2}, \text{User1} \}\)
Since order does not matter in sets,
Answer: \(A = B\)
Example 2: Are \(C = \{192.168.1.1, 192.168.1.2\}\) and \(D = \{192.168.1.2, 192.168.1.1\}\) equal?
Given:
\(C = \{192.168.1.1, 192.168.1.2\}\)
\(D = \{192.168.1.2, 192.168.1.1\}\)
Order is irrelevant for sets.
Answer: \(C = D\)
Example 3: Determine if \(E = \{A, B, C\}\) and \(F = \{C, B, A\}\) are equal.
Given:
\(E = \{A, B, C\}\)
\(F = \{C, B, A\}\)
Sets are unordered.
Answer: \(E = F\)
Example 4: Check if \(G = \{10, 20, 30\}\) equals \(H = \{30, 10, 20\}\).
Given:
\(G = \{10, 20, 30\}\)
\(H = \{30, 10, 20\}\)
Order does not affect sets.
Answer: \(G = H\)
Example 5: Are sets \(I = \{\text{Admin}, \text{Guest}\}\) and \(J = \{\text{Guest}, \text{Admin}\}\) equal?
Given:
\(I = \{\text{Admin}, \text{Guest}\}\)
\(J = \{\text{Guest}, \text{Admin}\}\)
Order irrelevant.
Answer: \(I = J\)
Sets contain no duplicate elements; repeated values are counted once.
Example 1: Simplify \(A = \{ \text{User1}, \text{User2}, \text{User1} \}\).
Given:
\(A = \{ \text{User1}, \text{User2}, \text{User1} \}\)
Duplicates removed:
$$ A = \{ \text{User1}, \text{User2} \} $$
Answer: \(A = \{ \text{User1}, \text{User2} \}\)
Example 2: Simplify \(B = \{192.168.1.1, 192.168.1.2, 192.168.1.1\}\).
Given:
\(B = \{192.168.1.1, 192.168.1.2, 192.168.1.1\}\)
Duplicates removed:
$$ B = \{192.168.1.1, 192.168.1.2\} $$
Answer: \(B = \{192.168.1.1, 192.168.1.2\}\)
Example 3: Simplify \(C = \{A, B, A, C, B\}\).
Given:
\(C = \{A, B, A, C, B\}\)
Duplicates removed:
$$ C = \{A, B, C\} $$
Answer: \(C = \{A, B, C\}\)
Example 4: Simplify \(D = \{10, 20, 10, 30, 20\}\).
Given:
\(D = \{10, 20, 10, 30, 20\}\)
Duplicates removed:
$$ D = \{10, 20, 30\} $$
Answer: \(D = \{10, 20, 30\}\)
Example 5: Simplify \(E = \{\text{Admin}, \text{Guest}, \text{Admin}, \text{User}\}\).
Given:
\(E = \{\text{Admin}, \text{Guest}, \text{Admin}, \text{User}\}\)
Duplicates removed:
$$ E = \{\text{Admin}, \text{Guest}, \text{User}\} $$
Answer: \(E = \{\text{Admin}, \text{Guest}, \text{User}\}\)
ICT technicians encounter different ways to represent sets depending on the context: roster, set-builder, and Venn diagram. Each method provides a distinct way to visualize or define data collections.
The roster method lists all elements explicitly inside braces.
Example 1: Represent the set of active servers \(S = \{ S1, S2, S3 \}\) in roster form.
Given:
Servers are \(S1, S2, S3\).
Roster form:
$$ S = \{ S1, S2, S3 \} $$
Answer: \(S = \{ S1, S2, S3 \}\)
Example 2: Represent user roles \(R = \{ \text{Admin}, \text{User}, \text{Guest} \}\).
Given:
Roles are Admin, User, Guest.
Roster form:
$$ R = \{ \text{Admin}, \text{User}, \text{Guest} \} $$
Answer: \(R = \{ \text{Admin}, \text{User}, \text{Guest} \}\)
Example 3: Represent IP addresses \(I = \{ 10.0.0.1, 10.0.0.2, 10.0.0.3 \}\).
Given:
IP addresses are 10.0.0.1, 10.0.0.2, 10.0.0.3.
Roster form:
$$ I = \{ 10.0.0.1, 10.0.0.2, 10.0.0.3 \} $$
Answer: \(I = \{ 10.0.0.1, 10.0.0.2, 10.0.0.3 \}\)
Example 4: Represent database tables \(T = \{ \text{Customers}, \text{Orders}, \text{Products} \}\).
Given:
Tables are Customers, Orders, Products.
Roster form:
$$ T = \{ \text{Customers}, \text{Orders}, \text{Products} \} $$
Answer: \(T = \{ \text{Customers}, \text{Orders}, \text{Products} \}\)
Example 5: Represent programming languages supported \(L = \{ \text{Python}, \text{Java}, \text{C++} \}\).
Given:
Languages are Python, Java, C++.
Roster form:
$$ L = \{ \text{Python}, \text{Java}, \text{C++} \} $$
Answer: \(L = \{ \text{Python}, \text{Java}, \text{C++} \}\)
The set-builder method defines a set by a property or rule that its members satisfy.
$$ A = \{ x \mid x \text{ has property } P \} $$
Example 1: Define the set of all IP addresses in the subnet 192.168.1.0 to 192.168.1.255.
Given:
IP addresses start with 192.168.1.
Set-builder form:
$$ A = \{ x \mid x \text{ is an IP address where } x = 192.168.1.i, 0 \leq i \leq 255 \} $$
Answer: \(A = \{ x \mid x = 192.168.1.i, 0 \leq i \leq 255 \}\)
Example 2: Define the set of even port numbers between 0 and 1024.
Given:
Ports are even numbers \(p\) such that \(0 \leq p \leq 1024\).
Set-builder form:
$$ B = \{ p \mid p \text{ is even}, 0 \leq p \leq 1024 \} $$
Answer: \(B = \{ p \mid p \text{ is even}, 0 \leq p \leq 1024 \}\)
Example 3: Define the set of users with access level above 3.
Given:
Users \(u\) with access level \(a > 3\).
Set-builder form:
$$ C = \{ u \mid \text{access level}(u) > 3 \} $$
Answer: \(C = \{ u \mid \text{access level}(u) > 3 \}\)
Example 4: Define the set of all usernames starting with "admin".
Given:
Usernames \(u\) where \(u\) starts with "admin".
Set-builder form:
$$ D = \{ u \mid u \text{ starts with "admin"} \} $$
Answer: \(D = \{ u \mid u \text{ starts with "admin"} \}\)
Example 5: Define the set of all devices with MAC addresses ending in "FF".
Given:
Devices \(d\) with MAC \(m\) ending in "FF".
Set-builder form:
$$ E = \{ d \mid \text{MAC}(d) \text{ ends with "FF"} \} $$
Answer: \(E = \{ d \mid \text{MAC}(d) \text{ ends with "FF"} \}\)
Venn diagrams are graphical representations showing relationships between sets using overlapping circles. They are useful in visualizing intersections, unions, and complements in network or database contexts.
Example 1: Draw a Venn diagram for sets \(A = \{1,2,3\}\), \(B = \{2,3,4\}\).
Given:
Set \(A\) and set \(B\) overlap at \(\{2,3\}\).
Answer: Venn diagram with two circles overlapping at elements 2 and 3.
Example 2: For user groups \(X = \{\text{Admin}, \text{User}\}\), \(Y = \{\text{User}, \text{Guest}\}\).
Given:
Both groups share "User".
Answer: Venn diagram with two overlapping circles sharing User.
Example 3: For device sets \(P = \{D1, D2\}\), \(Q = \{D2, D3\}\).
Given:
Common device is D2.
Answer: Venn diagram showing intersection at D2.
Example 4: For security groups \(M = \{\text{Read}, \text{Write}\}\), \(N = \{\text{Write}, \text{Execute}\}\).
Given:
Common permission: Write.
Answer: Venn diagram with overlapping Write permission.
Example 5: For IP address sets \(S = \{10.0.0.1, 10.0.0.2\}\), \(T = \{10.0.0.2, 10.0.0.3\}\).
Given:
Overlap at 10.0.0.2.
Answer: Venn diagram with intersection at 10.0.0.2.
Given sets \(A = \{1, 3, 5, 7\}\) and \(B = \{3, 4, 5, 6\}\), find \(A \cup B\), \(A \cap B\), and \(A - B\). (6 marks)
Verify the associative property for sets \(X = \{a, b\}\), \(Y = \{b, c\}\), and \(Z = \{c, d\}\) by calculating \((X \cup Y) \cup Z\) and \(X \cup (Y \cup Z)\). (4 marks)
Simplify the set \(S = \{ \text{User1}, \text{User2}, \text{User1}, \text{User3}, \text{User2} \}\) by removing duplicates. (2 marks)
Represent the set of all even numbers between 2 and 10 using the set-builder method. (3 marks)
For sets \(P = \{2, 4, 6\}\), \(Q = \{4, 5, 6\}\), verify the distributive property \(P \cap (Q \cup R) = (P \cap Q) \cup (P \cap R)\) where \(R = \{6, 7\}\). (5 marks)
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Create a free accountThis chapter introduced the fundamental concepts of set theory operations, beginning with how sets are represented and the key properties that define them, including order and uniqueness. Various methods of set representation were explored, such as roster form and set builder form, along with distinctions between finite and infinite sets. The chapter then discussed the different types of sets and their applications in mathematical contexts. Central to the chapter were the main set operations, including the determination of cardinality, union, intersection, difference, and complement of sets. The use of Venn diagrams was presented as a visual tool to illustrate these operations and relationships between sets. Overall, the chapter provided a comprehensive foundation for understanding and performing essential set theory operations in discrete mathematics.
Let set \(A = \{2, 4, 6, 8\}\) and set \(B = \{3, 4, 5, 6\}\). Find the cardinality of the union \(A \cup B\). (2 marks)
Given sets \(X = \{a, b, c, d, e\}\) and \(Y = \{c, d, e, f, g\}\), find the number of elements in the intersection \(X \cap Y\). (2 marks)
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