Page 16 - Math 7

Set

12. At first, let's list the elements of each of these sets from the diagrams. Then,
select the common elements and list them in separate sets.
a) A B b) P Q
3 1 4 m t i n

6 2 8 a h k

13. Let's list the elements and common elements of these pairs of sets and show
them in diagrams.
(a) A = { x : x is a whole number less than 10 }and B = { factors of 24 }
(b) P = { x : x is a multiple of 4, x ≤ 20 } and
Q = { x : x is a multiple of 5, x ≤ 20 }

It's your time - Project work!
14. a) Let's take a universal set under your consideration. Then, write as many
subsets as possible from your universal set.
b) Let's conduct a survey inside your classroom among your friends. Then,
list the name of your friends and make separate sets in the following cases:
(i) Sets of friends who like tea, coffee or milk.
(ii) Sets of friends who like Mo:Mo, chowmein or Thukpa.
(iii) How many overlapping sets are formed? Show them in diagrams.
(iv) How many disjoint sets are formed? Show them in diagrams.
(v) How many equal sets are formed?
(vi) How many equivalent sets are formed?
c) Is there any possibility to form overlapping sets of the sets of teachers
who are teaching different subjects in your school? If so, make these sets
and show in diagrams.
15. Let's make groups of 3 students and play game!
Each student of each group should make two disjoint sets with maximum
5 members taking the natural numbers from 1 to 20. Next day, from the sets
of numbers made by the students of each group, form as many number of
overlapping sets as possible. The group which has the maximum number of
overlapping sets is the winner!

1.8 Set Operations
Sets can be combined in a number of different ways to make another set. It is known
as set operations. There are four basis set operations. They are:
(i) Union of sets (ii ) Intersection of sets
(iii) Difference of sets (iv) Complement of a set
(i) Union of sets

Let's make a sport committee P with 3 members Ram, Sita, Laxmi and a
cultural committee Q with 4 members Sita, Laxman, Ajay, and Sudip. When
the committees P and Q have a joint meeting and a new committee R is

Vedanta Excel in Mathematics - Book 7 14 Approved by Curriculum Development Centre, Sanothimi, Bhaktapur