Maths-
General
Easy

Question

In a class of 30 pupils 12 take needls work, 16 take physics and 18 take history. If all the 30 students take at least one subject and no one takes all three, then the number of pupils taking 2 subjects is

  1. (a) 16  
  2. 6  
  3. 8  
  4. 20  

The correct answer is: (a) 16


    Given, n open parentheses N close parentheses equals 12 comma blank n open parentheses P close parentheses equals 16 comma blank n open parentheses H close parentheses equals 18,
    n open parentheses N union P union H close parentheses equals 30
    And n open parentheses N intersection P intersection H close parentheses equals 0
    Now, n open parentheses N union P union H close parentheses equals n open parentheses N close parentheses plus n open parentheses P close parentheses plus n open parentheses H close parentheses
    negative n open parentheses N intersection P close parentheses minus n open parentheses P intersection H close parentheses minus n open parentheses H intersection N close parentheses
    plus n left parenthesis N intersection P intersection H right parenthesis
    rightwards double arrow n open parentheses N intersection P close parentheses plus n open parentheses P intersection H close parentheses plus n open parentheses H intersection N close parentheses equals open parentheses 12 plus 16 plus 18 close parentheses minus 30
    equals 46 minus 30 equals 16

    Related Questions to study

    General
    Maths-

    If A equals left curly bracket x blank colon x is a multiple ofblank 4 right curly bracket and,
    B equals left curly bracket x blank colon x blankis a multiple ofblank 6 right curly bracket, then A intersection B consists of multiples of

    If A equals left curly bracket x blank colon x is a multiple ofblank 4 right curly bracket and,
    B equals left curly bracket x blank colon x blankis a multiple ofblank 6 right curly bracket, then A intersection B consists of multiples of

    Maths-General
    General
    Maths-

    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

    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

    Maths-General
    General
    Maths-

    Let Y equals open curly brackets 1 comma blank 2 comma blank 3 comma blank 4 comma blank 5 close curly brackets comma blank A open curly brackets 1 comma blank 2 close curly brackets comma blank B equals left curly bracket 3 comma blank 4 comma blank 5 right curly bracket and ϕ denotes null set. If left parenthesis A cross times B right parenthesis denotes cartesian product of the sets A and B; then open parentheses Y cross times A close parentheses intersection left parenthesis Y cross times B right parenthesis is

    Let Y equals open curly brackets 1 comma blank 2 comma blank 3 comma blank 4 comma blank 5 close curly brackets comma blank A open curly brackets 1 comma blank 2 close curly brackets comma blank B equals left curly bracket 3 comma blank 4 comma blank 5 right curly bracket and ϕ denotes null set. If left parenthesis A cross times B right parenthesis denotes cartesian product of the sets A and B; then open parentheses Y cross times A close parentheses intersection left parenthesis Y cross times B right parenthesis is

    Maths-General
    parallel
    General
    Maths-

    If A equals open curly brackets p element of N colon p blank i s blank a blank p r i m e blank a n d blank p equals fraction numerator 7 n to the power of 2 end exponent plus 3 n plus 3 over denominator n end fraction blank f o r blank s o m e blank n element of N close curly brackets comma then the number of elements in the set A comma is

    If A equals open curly brackets p element of N colon p blank i s blank a blank p r i m e blank a n d blank p equals fraction numerator 7 n to the power of 2 end exponent plus 3 n plus 3 over denominator n end fraction blank f o r blank s o m e blank n element of N close curly brackets comma then the number of elements in the set A comma is

    Maths-General
    General
    Maths-

    If A equals open curly brackets 1 comma blank 2 comma blank 3 comma blank 4 close curly brackets comma then the number of subsets of A that contain the element 2 but not 3, is

    If A equals open curly brackets 1 comma blank 2 comma blank 3 comma blank 4 close curly brackets comma then the number of subsets of A that contain the element 2 but not 3, is

    Maths-General
    General
    Maths-

    If A and B are two sets such that n open parentheses A close parentheses equals 7 comma n open parentheses B close parentheses equals 6 and open parentheses A intersection B close parentheses not equal to ϕ. The least possible value of n open parentheses A blank capital delta blank B close parentheses comma is

    If A and B are two sets such that n open parentheses A close parentheses equals 7 comma n open parentheses B close parentheses equals 6 and open parentheses A intersection B close parentheses not equal to ϕ. The least possible value of n open parentheses A blank capital delta blank B close parentheses comma is

    Maths-General
    parallel
    General
    Maths-

    If A equals open curly brackets a comma b comma blank c close curly brackets comma blank B equals left curly bracket b comma blank c comma blank d right curly bracket and C equals left curly bracket a comma blank d comma blank c right curly bracket, then open parentheses A minus B close parentheses cross times left parenthesis B intersection C right parenthesis is equal to

    If A equals open curly brackets a comma b comma blank c close curly brackets comma blank B equals left curly bracket b comma blank c comma blank d right curly bracket and C equals left curly bracket a comma blank d comma blank c right curly bracket, then open parentheses A minus B close parentheses cross times left parenthesis B intersection C right parenthesis is equal to

    Maths-General
    General
    Maths-

    Let A and B be two non-empty subsets of a set X such that A is not a subset of B. Then,

    Let A and B be two non-empty subsets of a set X such that A is not a subset of B. Then,

    Maths-General
    General
    Maths-

    If A and B are two sets, then A minus left parenthesis A minus B right parenthesis is equal to

    If A and B are two sets, then A minus left parenthesis A minus B right parenthesis is equal to

    Maths-General
    parallel
    General
    Maths-

    In a rehabilitation programme, a group of 50 families were assured new houses and compensation by the government. Number of families who got both is equal to the number of families who got neither of the two. The number of families who got new houses is 6 greater than the number of families who got compensation. How many families got houses?

    In a rehabilitation programme, a group of 50 families were assured new houses and compensation by the government. Number of families who got both is equal to the number of families who got neither of the two. The number of families who got new houses is 6 greater than the number of families who got compensation. How many families got houses?

    Maths-General
    General
    Maths-

    If A equals open curly brackets x comma y comma z close curly brackets comma then the relation
    R equals left curly bracket open parentheses x comma x close parentheses comma open parentheses y comma y close parentheses comma open parentheses z comma z close parentheses comma open parentheses z comma x close parentheses comma left parenthesis z comma y right parenthesis right curly bracket is

    If A equals open curly brackets x comma y comma z close curly brackets comma then the relation
    R equals left curly bracket open parentheses x comma x close parentheses comma open parentheses y comma y close parentheses comma open parentheses z comma z close parentheses comma open parentheses z comma x close parentheses comma left parenthesis z comma y right parenthesis right curly bracket is

    Maths-General
    General
    Maths-

    In an office, every employee likes at least one of tea, coffee and milk. The number of employees who like only tea, only coffee, only milk and all the three are all equal. The number of employees who like only tea and coffee, only coffee and milk and only tea and milk are equal and each is equal to the number of employees who like all the three. Then a possible value of the number of employees in the office is

    In an office, every employee likes at least one of tea, coffee and milk. The number of employees who like only tea, only coffee, only milk and all the three are all equal. The number of employees who like only tea and coffee, only coffee and milk and only tea and milk are equal and each is equal to the number of employees who like all the three. Then a possible value of the number of employees in the office is

    Maths-General
    parallel
    General
    Maths-

    Let U be the universal set for sets A and B such that n open parentheses A close parentheses equals 200 comma n open parentheses B close parentheses equals 300 and n open parentheses A intersection B close parentheses equals 100. Then, n left parenthesis A ´ intersection B ´ right parenthesis is equal to 300, provided that n left parenthesis blank U right parenthesis is equal to

    Let U be the universal set for sets A and B such that n open parentheses A close parentheses equals 200 comma n open parentheses B close parentheses equals 300 and n open parentheses A intersection B close parentheses equals 100. Then, n left parenthesis A ´ intersection B ´ right parenthesis is equal to 300, provided that n left parenthesis blank U right parenthesis is equal to

    Maths-General
    General
    Maths-

    A class has 175 students. The following data shows the number of students opting 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. Hoe many students have offered Mathematics alone?

    A class has 175 students. The following data shows the number of students opting 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. Hoe many students have offered Mathematics alone?

    Maths-General
    General
    Maths-

    If A and B are two sets such that n open parentheses A close parentheses equals 7 comma n open parentheses B close parentheses equals 6 and open parentheses A intersection B close parentheses not equal to ϕ. Then the greatest possible value of n open parentheses A blank capital delta blank B close parentheses comma is

    If A and B are two sets such that n open parentheses A close parentheses equals 7 comma n open parentheses B close parentheses equals 6 and open parentheses A intersection B close parentheses not equal to ϕ. Then the greatest possible value of n open parentheses A blank capital delta blank B close parentheses comma is

    Maths-General
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.