NCERT Solutions For Class 11 Computer Science Chapter 10 Tuples and Dictionaries - 2025-26

Exercise

1. Consider the following tuples, tuple1 and tuple2:
   

   tuple1 = (23,1,45,67,45,9,55,45)
   tuple2 = (100,200)
       

   Find the output of the following statements:
   1. print(tuple1.index(45))
      Answer: 2
   2. print(tuple1.count(45))
      Answer: 3
   3. print(tuple1 + tuple2)
      Answer: (23, 1, 45, 67, 45, 9, 55, 45, 100, 200)
   4. print(len(tuple2))
      Answer: 2
   5. print(max(tuple1))
      Answer: 67
   6. print(min(tuple1))
      Answer: 1
   7. print(sum(tuple2))
      Answer: 300
   8. print(sorted(tuple1))
      Answer: [1, 9, 23, 45, 45, 45, 55, 67]
   9. print(tuple1)
      Answer: (23, 1, 45, 67, 45, 9, 55, 45)
2. Consider the following dictionary stateCapital:

   stateCapital = {"AndhraPradesh":"Hyderabad",
   "Bihar":"Patna","Maharashtra":"Mumbai",
   "Rajasthan":"Jaipur"}
       

   Find the output of the following statements:
   1. print(stateCapital.get("Bihar"))
      Answer: Patna
   2. print(stateCapital.keys())
      Answer: dict_keys(['AndhraPradesh', 'Bihar', 'Maharashtra', 'Rajasthan'])
   3. print(stateCapital.values())
      Answer: dict_values(['Hyderabad', 'Patna', 'Mumbai', 'Jaipur'])
   4. print(stateCapital.items())
      Answer: dict_items([('AndhraPradesh', 'Hyderabad'), ('Bihar', 'Patna'), ('Maharashtra', 'Mumbai'), ('Rajasthan', 'Jaipur')])
   5. print(len(stateCapital))
      Answer: 4
   6. print("Maharashtra" in stateCapital)
      Answer: True
   7. print(stateCapital.get("Assam"))
      Answer: None
   8. del stateCapital["Rajasthan"]
      print(stateCapital)
      Answer: {'AndhraPradesh': 'Hyderabad', 'Bihar': 'Patna', 'Maharashtra': 'Mumbai'}
3. “Lists and Tuples are ordered”. Explain.
   Answer: In both lists and tuples, the elements are stored in a specific sequence. Each element has a fixed position, which is known as its index. This means we can access elements by their position, making lists and tuples ordered collections.
4. With the help of an example show how can you return more than one value from a function.
   Answer: In Python, a function can return multiple values by using a tuple. For example:

   def operation(a, b):
       sum = a + b
       product = a * b
       return sum, product
   
   x, y = operation(5, 3)
   print(x)   # Output: 8
   print(y)   # Output: 15
   

   In this example, the function returns both sum and product.
5. What advantages do tuples have over lists?
   Answer:
   • Tuples are immutable, so their elements cannot be changed by mistake.
   • Tuples are faster to process than lists.
   • Tuples can be used as keys in dictionaries, but lists cannot.
6. When to use tuple or dictionary in Python. Give some examples of programming situations mentioning their usefulness.
   Answer:
   • Use tuples when you need an ordered collection whose items should not change, like storing months of the year or RGB color codes.
   • Use dictionaries when you need to store data as key-value pairs, such as storing names and phone numbers or mapping student names to marks.
7. Prove with the help of an example that the variable is rebuilt in case of immutable data types.
   Answer:

   tuple1 = (1, 2, 3, 4, 5)
   tuple1[2] = 10  # This gives an error as tuples are immutable.
   # To change a value, rebuild the tuple:
   tuple1 = (1, 2, 10, 4, 5)  # The variable tuple1 is now rebuilt.
   

8. TypeError occurs while statement 2 is running. Give reason. How can it be corrected?

   >>> tuple1 = (5) #statement 1
   >>> len(tuple1) #statement 2
       

   Answer: In statement 1, tuple1 = (5) creates an integer, not a tuple. To create a single-element tuple, a comma is required: tuple1 = (5,). Now len(tuple1) will return 1.
   
   

Programming Problems

1. Write a program to read email IDs of n number of students and store them in a tuple. Create two new tuples, one to store only the usernames from the email IDs and second to store domain names from the email IDs. Print all three tuples at the end of the program. [Hint: You may use the function split()]

Answer:

def split_emails_to_tuples():
    n = int(input("How many emails? "))
    emails = []
    for i in range(n):
        emails.append(input(f"Email {i+1}: ").strip())
    emails_t = tuple(emails)

    usernames = []
    domains = []
    for e in emails_t:
        if "@" in e:
            u, d = e.split("@", 1)
        else:
            u, d = e, ""
        usernames.append(u)
        domains.append(d)

    usernames_t = tuple(usernames)
    domains_t = tuple(domains)

    print("Emails tuple:", emails_t)
    print("Usernames tuple:", usernames_t)
    print("Domains tuple:", domains_t)

# Example run:
# split_emails_to_tuples()

2. Write a program to input names of n students and store them in a tuple. Also, input a name from the user and find if this student is present in the tuple or not. We can accomplish these by: (a) writing a user defined function (b) using the built-in function

Answer:

# (a) User-defined search
def present_in_tuple(names_t, target):
    for name in names_t:
        if name.strip().lower() == target.strip().lower():
            return True
    return False

# (b) Built-in 'in'
def demo_names():
    n = int(input("How many names? "))
    names = [input(f"Name {i+1}: ") for i in range(n)]
    names_t = tuple(names)
    query = input("Search name: ")

    print("User-defined:", "Found" if present_in_tuple(names_t, query) else "Not found")
    print("Built-in:", "Found" if query in names_t else "Not found")

# demo_names()

3. Write a Python program to find the highest 2 values in a dictionary.

Answer:

def top_two_values(d):
    if len(d) < 2:
        raise ValueError("Need at least 2 items")
    # Get values sorted descending
    vals = sorted(d.values(), reverse=True)
    return vals[0], vals[1]

# Example:
# d = {"a": 10, "b": 4, "c": 25, "d": 25, "e": 3}
# print(top_two_values(d))  # (25, 25)

4. Write a Python program to create a dictionary from a string. Note: Track the count of the letters from the string. Sample string : 'w3resource' Expected output : {'3': 1, 's': 1, 'r': 2, 'u': 1, 'w': 1, 'c': 1, 'e': 2, 'o': 1}

Answer:

def char_count_dict(s):
    freq = {}
    for ch in s:
        freq[ch] = freq.get(ch, 0) + 1
    return freq

# Example:
# print(char_count_dict("w3resource"))
# {'w': 1, '3': 1, 'r': 2, 'e': 2, 's': 1, 'o': 1, 'u': 1, 'c': 1}

5. Write a program to input your friends’ names and their Phone Numbers and store them in the dictionary as the key-value pair. Perform the following operations on the dictionary: a) Display the name and phone number of all your friends b) Add a new key-value pair in this dictionary and display the modified dictionary c) Delete a particular friend from the dictionary d) Modify the phone number of an existing friend e) Check if a friend is present in the dictionary or not f) Display the dictionary in sorted order of names

Answer:

def phonebook_menu():
    pb = {}  # name -> phone

    while True:
        print("\n1) Display all\n2) Add\n3) Delete\n4) Modify\n5) Check presence\n6) Sorted by name\n0) Exit")
        ch = input("Choose: ").strip()

        if ch == "1":
            for n, p in pb.items():
                print(f"{n}: {p}")
        elif ch == "2":
            n = input("Name: ").strip()
            p = input("Phone: ").strip()
            pb[n] = p
            print("Added. Current:", pb)
        elif ch == "3":
            n = input("Name to delete: ").strip()
            if n in pb:
                del pb[n]
                print("Deleted.")
            else:
                print("Not found.")
        elif ch == "4":
            n = input("Name to modify: ").strip()
            if n in pb:
                pb[n] = input("New phone: ").strip()
                print("Updated.")
            else:
                print("Not found.")
        elif ch == "5":
            n = input("Name to check: ").strip()
            print("Present" if n in pb else "Absent")
        elif ch == "6":
            for n in sorted(pb):
                print(f"{n}: {pb[n]}")
        elif ch == "0":
            break
        else:
            print("Invalid choice")

# phonebook_menu()

Case Study-based Question

For the SMIS System given in Chapter 5, let us do the following: Write a program to take in the roll number, name and percentage of marks for n students of Class X. Write user defined functions to

• accept details of the n students (n is the number of students)
• search details of a particular student on the basis of roll number and display result
• display the result of all the students
• find the topper amongst them
• find the subject toppers amongst them

(Hint: use Dictionary, where the key can be roll number and the value is an immutable data type containing name and percentage) Let’s peer review the case studies of others based on the parameters given under “DOCUMENTATION TIPS” at the end of Chapter 5 and provide a feedback to them.

Answer:

# Core data model:
# db = {
#   roll: {"name": str, "percent": float, "subjects": {"Math": 92, "Sci": 84, ...}}
# }

def accept_students():
    n = int(input("Number of students: "))
    db = {}
    for _ in range(n):
        roll = input("Roll no: ").strip()
        name = input("Name: ").strip()
        percent = float(input("Overall %: "))
        subj_count = int(input("How many subjects? "))
        subjects = {}
        for i in range(subj_count):
            sname = input(f"  Subject {i+1} name: ").strip()
            smark = float(input(f"  Marks in {sname}: "))
            subjects[sname] = smark
        db[roll] = {"name": name, "percent": percent, "subjects": subjects}
    return db

def search_by_roll(db, roll):
    return db.get(roll)

def display_all(db):
    for roll, info in db.items():
        print(f"{roll} - {info['name']} - {info['percent']}% - {info['subjects']}")

def topper(db):
    # highest percent
    if not db: return None
    return max(db.items(), key=lambda kv: kv[1]["percent"])  # (roll, info)

def subject_toppers(db):
    # returns dict: subject -> (roll, name, marks)
    toppers = {}
    # collect all subjects
    subjects = set()
    for info in db.values():
        subjects.update(info["subjects"].keys())
    for s in subjects:
        best = None
        for roll, info in db.items():
            if s in info["subjects"]:
                m = info["subjects"][s]
                if best is None or m > best[2]:
                    best = (roll, info["name"], m)
        toppers[s] = best
    return toppers

# Example runner:
# db = accept_students()
# print(search_by_roll(db, input("Find roll: ")))
# display_all(db)
# print("Topper:", topper(db))
# print("Subject toppers:", subject_toppers(db))

Case Study-based Questions

1. A bank is a financial institution which is involved in borrowing and lending of money. With advancement in technology, online banking, also known as internet banking allows customers of a bank to conduct a range of financial transactions through the bank’s website anytime, anywhere. As part of initial investigation you are suggested to

• collect a bank’s application form. After careful analysis of the form, identify the information required for opening a savings account. Also enquire about the rate of interest offered for a saving account.

• The basic two operations performed on an account are Deposit and Withdrawal. Write a menu driven program that accepts either of the two choices of Deposit and Withdrawal, then accepts an amount, performs the transaction and accordingly displays the balance. Remember, every bank has a requirement of minimum balance which needs to be taken care of during withdrawal operations. Enquire about the minimum balance required in your bank.

• Collect the interest rates for opening a fixed deposit in various slabs in a savings bank account. Remember, rates may be different for senior citizens.

Finally, write a menu driven program having the following options (use functions and appropriate data types):

• Open a savings bank account
• Deposit money • Withdraw money
• Take details, such as amount and period for a Fixed Deposit and display its maturity amount for a particular customer.

Answer:

import math

class Account:
    def __init__(self, name, acc_no, min_balance=1000.0):
        self.name = name
        self.acc_no = acc_no
        self.balance = 0.0
        self.min_balance = min_balance

    def deposit(self, amt):
        if amt <= 0: raise ValueError("Invalid amount")
        self.balance += amt

    def withdraw(self, amt):
        if amt <= 0: raise ValueError("Invalid amount")
        if self.balance - amt < self.min_balance:
            raise ValueError("Cannot go below minimum balance")
        self.balance -= amt

def fd_maturity(principal, annual_rate_pct, years, compounding=4):
    r = annual_rate_pct / 100.0
    return round(principal * (1 + r/compounding) ** (compounding*years), 2)

def bank_menu():
    acc = None
    while True:
        print("\n1) Open Savings Account\n2) Deposit\n3) Withdraw\n4) Fixed Deposit Maturity\n0) Exit")
        ch = input("Choose: ").strip()
        try:
            if ch == "1":
                name = input("Name: "); acc_no = input("Acc No: ")
                min_bal = float(input("Min balance policy (ask bank): "))
                acc = Account(name, acc_no, min_bal)
                print("Account opened.")
            elif ch == "2":
                if not acc: print("Open account first"); continue
                amt = float(input("Amount: "))
                acc.deposit(amt); print("Balance:", acc.balance)
            elif ch == "3":
                if not acc: print("Open account first"); continue
                amt = float(input("Amount: "))
                acc.withdraw(amt); print("Balance:", acc.balance)
            elif ch == "4":
                P = float(input("Principal: "))
                rate = float(input("Annual rate % (slab/senior per bank): "))
                yrs = float(input("Years: "))
                print("FD Maturity:", fd_maturity(P, rate, yrs))
            elif ch == "0":
                break
            else:
                print("Invalid choice")
        except Exception as e:
            print("Error:", e)

# bank_menu()

2. Participating in a quiz can be fun as it provides a competitive element. Some educational institutes use it as a tool to measure knowledge level, abilities and/or skills of their pupils either on a general level or in a specific field of study. Identify and analyse popular quiz shows and write a Python program to create a quiz that should also contain the following functionalities besides the one identified by you as a result of your analysis.

• Create an administrative user ID and password to categorically add, modify, delete a question
• Register the student before allowing her or him to play a quiz
• Allow selection of category based on subject area
• Display questions as per the chosen category
• Keep the score as the participant plays
• Display the final score

Answer:

import getpass, random

ADMIN_USER = "admin"
ADMIN_PASS = "admin123"

# question bank: {category: [{"q":..., "opts":[...], "ans": 1-4}, ...]}
QB = {"General": [], "Science": [], "History": []}
REGISTERED = set()

def admin_portal():
    u = input("Admin user: ")
    p = getpass.getpass("Admin pass: ")
    if u != ADMIN_USER or p != ADMIN_PASS:
        print("Unauthorized"); return
    while True:
        print("\n1) Add Q  2) Modify Q  3) Delete Q  0) Exit")
        ch = input("Choose: ")
        if ch == "1":
            cat = input(f"Category {list(QB.keys())}: ")
            q = input("Question: ")
            opts = [input("Opt 1: "), input("Opt 2: "), input("Opt 3: "), input("Opt 4: ")]
            ans = int(input("Correct option (1-4): "))
            QB.setdefault(cat, []).append({"q": q, "opts": opts, "ans": ans})
            print("Added.")
        elif ch == "2":
            cat = input("Category: "); idx = int(input("Q index (0-based): "))
            if cat in QB and 0 <= idx < len(QB[cat]):
                QB[cat][idx]["q"] = input("New question: ")
                print("Modified.")
            else:
                print("Not found.")
        elif ch == "3":
            cat = input("Category: "); idx = int(input("Q index (0-based): "))
            if cat in QB and 0 <= idx < len(QB[cat]):
                QB[cat].pop(idx); print("Deleted.")
            else:
                print("Not found.")
        elif ch == "0":
            break

def register_student():
    name = input("Student name: ").strip()
    REGISTERED.add(name)
    print("Registered:", name)
    return name

def play_quiz(student):
    if student not in REGISTERED:
        print("Please register first."); return
    cat = input(f"Choose category {list(QB.keys())}: ")
    if cat not in QB or not QB[cat]:
        print("No questions in this category."); return
    score = 0
    for q in random.sample(QB[cat], k=len(QB[cat])):
        print("\n", q["q"])
        for i, opt in enumerate(q["opts"], 1):
            print(f"{i}. {opt}")
        try:
            ans = int(input("Your choice (1-4): "))
            if ans == q["ans"]:
                score += 1
        except:
            pass
    print(f"Final score: {score}/{len(QB[cat])}")

# Example flow:
# admin_portal(); s = register_student(); play_quiz(s)

3. Our heritage monuments are our assets. They are a reflection of our rich and glorious past and an inspiration for our future. UNESCO has identified some of Indian heritage sites as World heritage sites. Collect the following information about these sites:

• What is the name of the site? • Where is it located?
      ▪ District
      ▪ State
• When was it built? • Who built it?
• Why was it built? • Website link (if any).

Write a Python program to
• create an administrative user ID and password to add, modify or delete an entered heritage site in the list of sites
• display the list of world heritage sites in India
• search and display information of a world heritage site entered by the user
• display the name(s) of world heritage site(s) on the basis of the state input by the user.

Answer:

import getpass

ADMIN_U, ADMIN_P = "admin", "secret"
# sites_db: {site_name: {"district":..., "state":..., "year":..., "builder":..., "purpose":..., "url":...}}
sites_db = {}

def admin_login():
    u = input("Admin user: "); p = getpass.getpass("Admin pass: ")
    return u == ADMIN_U and p == ADMIN_P

def admin_manage():
    if not admin_login():
        print("Unauthorized"); return
    while True:
        print("\n1) Add  2) Modify  3) Delete  0) Exit")
        ch = input("Choose: ")
        if ch == "1":
            name = input("Site name: ")
            sites_db[name] = {
                "district": input("District: "),
                "state": input("State: "),
                "year": input("When built: "),
                "builder": input("Who built: "),
                "purpose": input("Why built: "),
                "url": input("Website link (if any): ")
            }
            print("Added.")
        elif ch == "2":
            name = input("Site name to modify: ")
            if name in sites_db:
                key = input("Field (district/state/year/builder/purpose/url): ")
                if key in sites_db[name]:
                    sites_db[name][key] = input(f"New value for {key}: ")
                    print("Updated.")
                else:
                    print("Bad field.")
            else:
                print("Not found.")
        elif ch == "3":
            name = input("Site name to delete: ")
            print("Deleted.") if sites_db.pop(name, None) else print("Not found.")
        elif ch == "0":
            break

def list_sites():
    if not sites_db: print("No sites."); return
    for n in sites_db:
        print("-", n)

def search_site(name):
    info = sites_db.get(name)
    if not info: print("Not found."); return
    print(name, "->", info)

def sites_by_state(state):
    names = [n for n, v in sites_db.items() if v["state"].lower() == state.lower()]
    print("Sites:", names or "None")

# Example usage:
# admin_manage(); list_sites(); search_site("Taj Mahal"); sites_by_state("Uttar Pradesh")

4. Every mode of transport utilises a reservation system to ensure its smooth and efficient functioning. If you analyse you would find many things in common. You are required to identify any one mode of transportation and prepare a reservation system for it. For example, let us look at the Railway reservation system we talked about earlier. The complex task of designing a good railway reservation system is seen as designing the different components of the system and then making them work with each other efficiently. Possible sub- systems are shown in Figure 1. Each of them may be modelled using functions.

Write a python code to automate the reservation needs of the identified mode of transport.

Answer:

# Minimal railway-like reservation scaffold (extend as needed)
from collections import defaultdict

trains = {
    "12001": {"name": "Shatabdi", "days": ["Mon","Wed","Fri"], "classes": {"CC": 3, "EC": 1}},
    # classes hold coach counts; assume each coach has 70 seats (simple)
}
inventory = defaultdict(lambda: defaultdict(int))  # (train, class) -> seats booked

SEATS_PER_COACH = 70

def total_capacity(train_no, cls):
    t = trains[train_no]
    return t["classes"][cls] * SEATS_PER_COACH

def seats_available(train_no, cls):
    cap = total_capacity(train_no, cls)
    return cap - inventory[train_no][cls]

def book(train_no, cls, qty):
    if seats_available(train_no, cls) >= qty:
        inventory[train_no][cls] += qty
        return True
    return False

def cancel(train_no, cls, qty):
    booked = inventory[train_no][cls]
    if qty <= booked:
        inventory[train_no][cls] -= qty
        return True
    return False

def fare(train_no, cls, qty):
    base = {"CC": 650, "EC": 1200}[cls]
    return base * qty

# Example flow:
# print("Avail:", seats_available("12001","CC"))
# print("Book:", book("12001","CC", 5), "Fare:", fare("12001","CC",5))
# print("Avail:", seats_available("12001","CC"))
# print("Cancel:", cancel("12001","CC", 2))
# print("Avail:", seats_available("12001","CC"))

Mastering Tuples and Dictionaries in Python

NCERT Solutions Computer Science Chapter 10 Tuples And Dictionaries (2025-26) help you understand how tuples and dictionaries work in Python. These structures are essential for storing data efficiently and tackling higher-level programming tasks at school and beyond.

By practicing with NCERT exercises, you'll discover the key differences between mutable and immutable types. Recognizing real-world uses for these Python concepts gives you an edge in solving computer science questions with speed and accuracy.

Consistent revision of chapter-wise NCERT solutions strengthens your foundational knowledge. Revise important examples, focus on practical applications, and you'll be well-prepared to score better in the exam!

CBSE Class 11 Computer Science Chapter-wise NCERT Solutions

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