diff --git a/Introduction-to-Data-Science/Session-6/aakash_singh/q10.py b/Introduction-to-Data-Science/Session-6/aakash_singh/q10.py
new file mode 100644
index 0000000..8f160e1
--- /dev/null
+++ b/Introduction-to-Data-Science/Session-6/aakash_singh/q10.py
@@ -0,0 +1,35 @@
+class person:
+    def __init__(self, first_name='', last_name='', phone_number='', email=[]):
+        self.first_name = first_name
+        self.last_name = last_name
+        self.phone_number = phone_number
+        self.email = email
+
+    def __str__(self):
+        s = self.first_name+' '+self.last_name+'\n'+self.phone_number+'\n'
+        for e in self.email:
+            s += e+'\n'
+        return s.strip()
+
+    def __repr__(self):
+        return self.__str__()
+
+
+class address_book:
+    def __init__(self):
+        self.ad_book = []
+
+    def add_contact(self):
+        newPerson = person()
+        newPerson.first_name = input('first name: ')
+        newPerson.last_name = input('last name: ')
+        newPerson.phone_number = input('phone number: ')
+        for i in range(int(input('enter number of email: '))):
+            newPerson.email.append(input('email {}: '.format(i+1)))
+        self.ad_book.append(newPerson)
+
+    def lookup_contact(self, ln):
+        for i in self.ad_book:
+            if ln == i.last_name:
+                print(i)
+                return
\ No newline at end of file
diff --git a/Introduction-to-Data-Science/Session-6/aakash_singh/q9.py b/Introduction-to-Data-Science/Session-6/aakash_singh/q9.py
new file mode 100644
index 0000000..6ca0335
--- /dev/null
+++ b/Introduction-to-Data-Science/Session-6/aakash_singh/q9.py
@@ -0,0 +1,43 @@
+import random
+
+
+class deck:
+    class card:
+        def __init__(self, suit, val):
+            self.suit = suit
+            self.val = val
+
+        def __str__(self):
+            return '{} {}'.format(self.suit, self.val)
+
+        def __repr__(self):
+            return self.__str__()
+
+    __suits = ['Hearts', 'Diamonds', 'Clubs', 'Spades']
+    __values = ['A', '2', '3', '4', '5', '6',
+                '7', '8', '9', '10', 'J', 'Q', 'K']
+
+    Deck = []
+
+    def deal(self,suit,value):
+        i=0
+        for i in range(len(self.Deck)):
+            if self.Deck[i].suit==suit and self.Deck[i].val==value:
+                del self.Deck[i]
+                print('del')
+                return
+
+    def __init__(self):
+        random.seed()
+        for i in self.__suits:
+            for j in self.__values:
+                self.Deck.append(self.card(i, j))
+
+    def swap(self, a, b):
+        self.Deck[a], self.Deck[b] = self.Deck[b], self.Deck[a]
+
+    def shuffle(self):
+        if len(self.Deck) != 52:
+            self.__init__()
+        for i in range(1000):
+            self.swap(random.randrange(0, 52), random.randrange(0, 52))
\ No newline at end of file
diff --git a/Introduction-to-Data-Science/Session-6/aakash_singh/theory.txt b/Introduction-to-Data-Science/Session-6/aakash_singh/theory.txt
new file mode 100644
index 0000000..06c5b7e
--- /dev/null
+++ b/Introduction-to-Data-Science/Session-6/aakash_singh/theory.txt
@@ -0,0 +1,28 @@
+q1:
+    Class implements the OOP concept in python. It provides a way to encapsulate all data and methods related to an object into one package.
+
+q2:
+    An instance in python is a class object that has all the attributes described in the class definition.
+
+q3:
+    A class defines how the object should work and all its attributes.
+    An instance is the implementation of the class definition in a code.
+
+q4:
+    class newClass(inheritClass):
+        attributes
+
+q5:
+    any function that is defined inside the class of the object is called a method of the object.
+
+q6:
+    self is a way in python class to refer to the attributes of the object.
+    This helps segregate method parametres from the object member functions.
+
+q7:
+    __init__ is a method which is equivalent to a constructor in c++.
+    __init__ is called whenever a new object of the class is formed and it initializes the object.
+
+q8:
+    the derived class inherits from a base class. In this process the the attributes of the base class are available to the object of the derived class.
+    This prevents code duplication and encourages code reuse.
\ No newline at end of file