Here we have given the solutions of some important questions of chapter 1 (Set Theory) of NCERT Exemplar book .
Short answer type questions
1. Write the following sets in the roaster form
Sol. (i) On solving the equation , we get
(ii) gives which implies
(iii) Since every prime no. has only two factors 1 and number itself. This implies
2. Write the following sets in the roaster form:
Sol. (i) On solving , we get , which implies either or .
It gives .
(iii) We have
This implies .
Q3. If . Write in the roaster form.
Since is prime number , it has only two factors 1 and ( ) and the factors of are 1,2,22,23,…, . Therefore .
Q4. , and are subsets of Universal Set . If and is the set of all whole numbers, draw a Venn diagram showing the relation of and .
Therefore , , and .
Hence, the Venn diagram showing relation of given sets is:
5. Determine whether the statement given below is true or false. Justify your answer.
For all sets , and ,
Solution: Let ,
then . This implies …………..(i)
Now , this implies …………..(ii)
From (i) and (ii) , it is clear that .
We can also show that the given expression is false by using Venn Diagrams
Now, from the Venn diagrams, it is clear that .