Easy2Siksha.com
city streets. Every formula, every equation, tells a story — and once you learn to listen,
math becomes your best friend.
4. (i) Define sets. Explain various types of sets.
(ii) Explain union, intersection, difference and symmetric difference of sets.
(iii) A class of 70 students, out of which 30 have Maths and 20 have taken Maths but not
Statistics. Find no. of students who have taken Maths and Statistics and those who have
taken Statistics but not Maths.
Ans: A Journey Through the World of Sets
Let’s begin our learning journey not in a classroom, but in a magical library of knowledge,
where each book represents a student, and each bookshelf represents a set. Imagine this
library is managed by a curious boy named Aryan, who loves to observe patterns, organize
information, and solve puzzles. One day, while helping his teacher arrange files about
students who opted for Maths and Statistics, he discovered something wonderful — Set
Theory!
Let’s walk with Aryan as he discovers what sets are, the different types of sets, and how we
perform operations like union, intersection, difference, and symmetric difference. At the
end, we’ll also help Aryan solve a real-life problem using this knowledge. Are you ready?
Let’s go!
(i) What is a Set?
A set is simply a collection of well-defined and distinct objects. These objects are called
elements or members of the set. The best part? You can write a set using curly brackets { }.
Definition:
A set is a well-defined collection of objects. The elements of a set are written within curly
braces, separated by commas.
Examples:
• A set of vowels in the English alphabet:
A = {a, e, i, o, u}
• A set of first five natural numbers:
B = {1, 2, 3, 4, 5}
• A set of colors in the rainbow:
C = {red, orange, yellow, green, blue, indigo, violet}