Q2 of 145 Page 47

If A = ϕ then write P(A).

The power set of set A is a collection of all subsets of A.


Here A = {ϕ}


Hence the subset of A will only be a null set ϕ


Hence P(A) = {ϕ}


More from this chapter

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15

A class has 175 students. The following description gives the number of students one or more of the subjects in this class: mathematics 100, physics 70, chemistry 46, mathematics and physics 30; mathematics and chemistry 28; physics and chemistry 23; mathematics, physics and chemistry 18. Find

(i) how many students are enrolled in mathematics alone, physics alone and chemistry alone,


(ii) The number of students who have not offered any of these subjects.


 1

If a set A and n elements then find the number of elements in its power set P(A).

 3

If n(A) = 3 and n(B) = 5, find:

(i) The maximum number of elements in A ∪ B,


(ii) The minimum number of elements in A ∪ B.


 4

If A and B are two sets such than n(A) = 8, n(B) = 11 and n(A ∪ B) = 14 then find n(A ∩ B).