sets/questions.rst
author Anoop Jacob Thomas<anoop@fossee.in>
Tue, 12 Oct 2010 16:26:36 +0530
changeset 308 0a0a91fb3a0d
parent 233 ab748264f726
permissions -rw-r--r--
added slides for other-type-of-plots.

Objective Questions
-------------------

 1. If ``a = [1, 1, 2, 3, 3, 5, 5, 8]``. What is set(a)

   a. set([1, 1, 2, 3, 3, 5, 5, 8])
   #. set([1, 2, 3, 5, 8])
   #. set([1, 2, 3, 3, 5, 5])
   #. Error

   Answer: set([1, 2, 3, 5, 8])

 2. ``a = set([1, 3, 5])``. How do you find the length of a?

   Answer: len(a)

 3. ``a = set([1, 3, 5])``. What does a[2] produce?

   a. 1
   #. 3
   #. 5
   #. Error

   Answer: Error

 4. ``odd = set([1, 3, 5, 7, 9])`` and ``squares = set([1, 4, 9, 16])``. What
    is the value of ``odd | squares``?

   Answer: set([1, 3, 4, 5, 7, 9, 16])

 5. ``odd = set([1, 3, 5, 7, 9])`` and ``squares = set([1, 4, 9, 16])``. What
    is the value of ``odd - squares``?

   Answer: set([3, 5, 7])

 6. ``odd = set([1, 3, 5, 7, 9])`` and ``squares = set([1, 4, 9, 16])``. What
    is the value of ``odd ^ squares``?

   Answer: set([3, 4, 5, 7, 16])

 7. ``odd = set([1, 3, 5, 7, 9])`` and ``squares = set([1, 4, 9, 16])``. What
    does ``odd * squares`` give?

   a. set([1, 12, 45, 112, 9])
   #. set([1, 3, 4, 5, 7, 9, 16])
   #. set([])
   #. Error

   Answer: Error

 8. ``a = set([1, 2, 3, 4])`` and ``b = set([5, 6, 7, 8])``. What is ``a + b``

   a. set([1, 2, 3, 4, 5, 6, 7, 8])
   #. set([6, 8, 10, 12])
   #. set([5, 12, 21, 32])
   #. Error

 9. ``a`` is a set. how do you check if if a varaible ``b`` exists in ``a``?

   Answer: b in a

 10. ``a`` and ``b`` are two sets. What is ``a ^ b == (a - b) | (b - a)``?

   a. True
   #. False

   Answer: False


Larger Questions
----------------

 1. Given that mat_marks is a list of maths marks of a class. Find out the
    no.of duplicates marks in the list.

   Answer::

     unique_marks = set(mat_marks)
     no_of_duplicates = len(mat_marks) - len(unique_marks)

 2. Given that mat_marks is a list of maths marks of a class. Find how many
    duplicates of each mark exist.

   Answer::

     marks_set = set(mat_marks)
     for mark in marks_set:
         occurences = mat_marks.count(mark)
         print occurences - 1, "duplicates of", mark, "exist"