Sets CBSE Questions & Answers

Sets

This is Mathematics Class 11 Sets CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
In a town of 10,000 families it was found that 40\(\% \) families buys newspaper A , 20\(\% \) buy newspaper B , and 10\(\% \) families buy newspaper C , 5\(\% \) families buy A and B , 3\(\% \) buy B and C and 4\(\% \) buy A and C . If 2\(\% \) buy all the three newspapers , then number of families which buy A only is
  • A
    1400
  • B
    2900
  • C
    3300
    Correct
  • D
    3100
2
In the above question, the number of families which buy none of A , B , C is
  • A
    4000
    Correct
  • B
    5000
  • C
    3300
  • D
    4200
3
In a battle 70\(\% \) of combatants lost one eye , 80\(\% \) an ear , 75\(\% \) an arm , 85\(\% \) a leg ,x\(\% \) lose all the four limbs. The minimum value of x is :
  • A
    12
  • B
    10
    Correct
  • C
    15
  • D
    none of these.
4
f A = { \(\emptyset \) , { \(\emptyset \) } } , then the power set of A is
  • A
    { \(\emptyset \) , A }
  • B
    { \(\emptyset \) ,{ \(\emptyset \) } , { { \(\emptyset \) } } , A }
    Correct
  • C
    A
  • D
    { \(\emptyset \) , { \(\emptyset \) } , A }
5
If aN = { ax : x \( \in \) N } and bN \(\mathop \cap \nolimits \) cN = dN , where b, c \( \in \) N are relatively prime , then
  • A
    d = bc
    Correct
  • B
    none of these
  • C
    c = bd
  • D
    b = cd
6
Let A and B be two non- empty subsets of a set X such that A is not a subset of B , then
  • A
    none of these
  • B
    A and the complement of B are always non-disjoint
    Correct
  • C
    B is always a subset of A
  • D
    A and B are always disjoint
7
If A class has 175 students . The following data shows the number of students offering one or more subjects. Mathematics 100 ; Physics 70 ; Chemistry 40 ; Mathematics and Physics 30 ; Mathematics and Chemistry 28 ; Physics and Chemistry 23 ; Mathematics , Physics and Chemistry 18 . How many students have offered Mathematics alone ?
  • A
    48
  • B
    22.
  • C
    60
    Correct
  • D
    35
8
If A = { \((x,y):{x^2} + {y^2} = 25\) } and B = { \((x,y):{x^2} + 9{y^2} = 144\) } then A\(\mathop \cap \nolimits \) B contains
  • A
    one point
  • B
    four points
    Correct
  • C
    three points
  • D
    two points
9
In a city 20\(\% \) of the population travels by car , 50 \(\% \) travels by bus and 10% travels by both car and bus . Then persons travelling by car or bus is
  • A
    80\(\% \)
  • B
    30\(\% \)
  • C
    60\(\% \)
    Correct
  • D
    20\(\% \)
10
Let A and B be two sets such that n ( A ) = 0.16 , n ( B ) = 0.14 ,n ( A \(\mathop \cup \nolimits \) B ) = 0.25 , then n ( A \(\mathop \cap \nolimits \) B ) is equal to
  • A
    0.3
  • B
    0.05
    Correct
  • C
    none of these
  • D
    0.5
11
If A = { x : x is a multiple of 3 } and B = { x : x is a multiple of 5 } , then A – B is
  • A
    ( A\(\mathop \cap \nolimits \) B )’
  • B
    A \(\mathop \cap \nolimits \) B’
    Correct
  • C
    A’\(\mathop \cap \nolimits \) B’
  • D
    A’\(\mathop \cap \nolimits \) B
12
The set of all prime numbers is
  • A
    a finite set
  • B
    a singleton set
  • C
    none of these
  • D
    an infinite set
    Correct
13
The set A = { x : x is a positive prime less than 10 } in the tabular form is
  • A
    { 1 , 3 , 5 , 7 , 9 }
  • B
    none of these.
  • C
    { 1, 2 , 3 , 5 , 7 }
  • D
    { 2 , 3 , 5 , 7 }
    Correct
14
Which of the following is a null set ?
  • A
    \({\text{B }} = \left\{ {{\text{ x }}:{\text{ x }} + {\text{ 3 }} = {\text{ 3 }}} \right\}\)
  • B
    C = { \(\phi \) }
  • C
    none of these.
  • D
    \({\text{A }} = {\text{ }}\left\{ {{\text{ x }}:{\text{ x }} > {\text{ 1 and x}} < {\text{ 1 }}} \right\}\)
    Correct
15
The set of intelligent students in a class is
  • A
    a finite set
  • B
    a singleton set.
  • C
    a null set
  • D
    not a well defined collection
    Correct