Functions-GATE Questions


  • 2

    At 23:00 , we say that f(EUF) = f(E) U f(F)


    Sir, when you give the example Wives(Indians U Software Engineer) = Wives(Indians) U Wives(Software Engineer) , dont we need to subtract the components where Wives(Indian Software engineer) as this will be repeated

    • raadjosePRO

      Also given that E and F are both subsets of A, there is bound to be common elements between them.

      Or do we ignore the duplicate items because it is a set, and duplicate items are not included in set.

    • getgatebook

      when A = {1,2,3} and B = {1,5,6} A U B = {1,2,3,5,6}. Here union operation automatically eliminates duplicates as that is the way set union is defined.

  • 1



    sir, you have given a counter example with an element 7. wat if 7 has a
    different image in C than all the elements in B

    • getgatebook

      If 7 is mapped to new element 11 then h is not on to right ? But in the question it is given that h is on to.
      One more point, some how if you find an arrangement such that h is on to and f and g both are on to then we can not say option D is correct. Think why ?

  • 1

    At 10:00 2nd gate problem


    all n subsets X1, X2, … Xn are of size 3.
    So total number of elements in Xj in 3n.
    So ans = 3n
    is it correct? Summing up the no of elements in all Xj gives nothing but the count of repetitions of all the elements of S

    • getgatebook

      Yes, you are absolutely correct.