NCERT Class 11-Math՚S Exemplar Chapter 1 Sets CBSE Board Problems (For CBSE, ICSE, IAS, NET, NRA 2022)

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Question 27:

In a town of families it was found that 40 % families buy newspaper A, families buy newspaper B, families buy newspaper C, families buy A and B, buy B and C and 4 % buy A and C. If 2 % families buy all the three newspapers. Find

(a) The number of families which buy newspaper A only.

(b) The number of families which buy none of A, B and C

Answer:

(a) 3300

(b) 4000

Question 28:

In a group of 50 students, the number of students studying French, English, Sanskrit were found to be as follows:

French and Sanskrit , English, French and Sanskrit . Find the number of students who study

(i) French only

(ii) English only

(iii) Sanskrit only

(iv) English and Sanskrit but not French

(v) French and Sanskrit but not English

(vi) French and English but not Sanskrit

(vii) at least one of the three languages

(viii) none of the three languages

Answer:

(i) 6

(ii) 3

(iii) 9

(iv) 1

(v) 2

(vi) 6

(vii) 30

(viii) 20

Objective Type Questions

Choose the correct answers from the given four options in each Exercises 29 to 43 (M. C. Q.) .

Question 29:

Suppose are thirty sets each having 5 elements and are n sets each with 3 elements,

and each element of S belongs to exactly 10 of the Ai ‘s and exactly 9 of the B,’ S. then n is equal to

(A) 15

(B) 3

(C) 45

(D) 35

Answer: (C)

Question 30:

Two finite sets have m and n elements. The number of subsets of the first set is 112 more than that of the second set. The values of m and n are, respectively,

(A) 4,7

(B) 7,4

(C) 4,4

(D) 7,7

Answer: (B)

Question 31:

The is equal to

(A)

(B)

(C)

(D)

Answer: (B)

Question 32:

Let be the set of parallelograms, the set of rectangles, the set of rhombuses, the set of squares and the set of trapeziums in a plane. Then may be equal to

(A)

(B)

(C)

(D)

Answer: (D)

Question 33:

Let set of points inside the square, the set of points inside the triangle and the set of points inside the circle. If the triangle and circle intersect each other and are contained in a square. Then

(A)

(B)

(C)

(D)

Answer: (C)