Final Exam Model Paper 2

i. The function returns two values, a tuple, and line 10 puts them in made and boundaries: 1 + 4 + 0 + 4 + 6 + 2 = 17 runs, with two fours.

17 2

ii. total is a local variable of summary: it exists only while the function runs, and is gone when it returns. Outside the function there is no name total, so line 12 gives NameError: name 'total' is not defined. The function gave its total back with return, and it is now in made, so Aarav should write print(made).

• i.In a tree there is exactly one route between any two places: each tap gets its water from one place above it, its parent, through one pipe. A burst pipe breaks the only route from the tank to every tap below it, so all of them go dry.
• ii.The new pipe makes a loop: there are now two routes to the taps on that loop, so when one of their pipes bursts the water can come round the other way. A tree has no loops (with 10 places it has exactly 9 pipes, and now there are 10), so the pipes are no longer a tree.

SELECT item, SUM(plates)FROM salesGROUP BY itemHAVING SUM(plates) > 100ORDER BY SUM(plates) DESC;

The condition is on each item’s total, a group, so it goes in HAVING, after GROUP BY. WHERE plates > 100 would instead keep only single sales of more than 100 plates.

import pandas as pd results = pd.read_csv("results.csv")fast = results[(results["event"] == "100 m") & (results["seconds"] < 14)]print(fast[["name", "house", "seconds"]].sort_values("seconds"))

     name   house  seconds1   Bibek    Blue     12.94   Eliza  Yellow     13.20  Anisha     Red     13.8

Each condition is in its own brackets, joined by & (both must be true). The numbers on the left are the rows’ places in the whole file.

404 Not Found means Nirmala’s computer reached the website, and the website answered, but there is no page at that address. She should check the address she typed (or followed from a link), or go to the site’s home page and look for the page from there.
This site can’t be reached means Suman’s computer is connected, but the site itself can’t be found or isn’t answering. He should check the spelling of the address, then try another website: if others open, the problem is with that site (or its name), not with his connection.

• i.Three folders, called Sports, Day and 2026. In the shell a space separates arguments, so mkdir was given three names and made a folder for each. For the same reason, cd was given three arguments, and it can go to only one folder.
• ii.Put the name in quotes, so the shell reads it as one argument:

mkdir "Sports Day 2026"cd "Sports Day 2026"

• i.The tokenizer learned its pieces by joining the commonest pairs in its training text, which was mostly English. English words became one token each, but few Nepali pieces were learned, so Nepali text is cut into small pieces: single letters and vowel signs, or even pieces of a letter’s bytes (a Devanagari letter is three bytes in UTF-8).
• ii.Any one: a Nepali conversation fills the context window sooner, so in a long chat the model loses sight of the earliest messages sooner; the answer takes longer to write, token by token; the model may be less reliable in Nepali, since Nepali was rare in its training text.

Job (b), the percentages. Judge each job’s harm:

• How bad a mistake would be: a wrong percentage can change a student’s grade, or pass and fail, on an official record; a dull house name harms nobody.
• How likely it is to be acted on without checking: the numbers go straight onto report cards, while the notice is read by the head teacher first.
• Who is harmed: every student and their family, who may not find out or be able to recover.
• And language models are weak at exact arithmetic: they see numbers as tokens and predict likely digits, so they can be confidently wrong. Percentages are better worked out by a spreadsheet or a program, and checked.

A portfolio is a collection of your best work that shows what you can do, because clients pay for skills they can see. A student could put in, for example: a program they wrote, a website made for someone, a data analysis with its charts, a design, their Unit 8 team project.

It is a weak rule. It names one product, so it isn’t technology-neutral: other chatbots, and AI inside other apps, aren’t covered, and next year’s tools won’t be either. It can’t be enforced: a teacher can’t tell for sure who used it. And it blocks good uses too, such as asking for a hard idea to be explained another way.
A better rule says what matters, for any tool: “Work you hand in must be your own. If you use an AI tool, say which one and what you used it for. AI tools may not be used in tests. A teacher may ask you to explain any work you hand in.”

i. and ii.

"""Run rates for the tournament's scoreboard.""" BALLS_PER_OVER = 6  def run_rate(runs, balls):    """Runs per over so far, to 2 decimal places (0 before the first ball)."""    if balls == 0:        return 0    return round(runs / balls * BALLS_PER_OVER, 2)  def needed_rate(target, runs, balls_left):    """Runs per over still needed to reach target; 0 once it is reached,    None if no balls are left."""    still_needed = target - runs    if still_needed <= 0:        return 0    if balls_left == 0:        return None    return round(still_needed / balls_left * BALLS_PER_OVER, 2)  if __name__ == "__main__":    # tests: an ordinary case, and the three special cases    print(run_rate(30, 18), "should be 10.0")    print(run_rate(0, 0), "should be 0")    print(needed_rate(100, 88, 12), "should be 6.0")    print(needed_rate(100, 100, 6), "should be 0")    print(needed_rate(100, 90, 0), "should be None")

iii.

import cricket print("Run rate:", cricket.run_rate(87, 70))print("Needed rate:", cricket.needed_rate(142, 87, 50))

Run rate: 7.46Needed rate: 6.6

87 runs in 70 balls is 87 ÷ 70 × 6 ≈ 7.46 runs an over. The team still needs 142 − 87 = 55 runs from 50 balls: 55 ÷ 50 × 6 = 6.6 an over. The check for a reached target must come before the check for no balls left: a team that won on the last ball needs 0, not None. Any clear names and messages are fine.

i.

• ii.4 trails. Danda was first reached from Lamagaun, Lamagaun from Phedi, Phedi from Deurali, Deurali from the Ward office: Ward office → Deurali → Phedi → Lamagaun → Danda.
• iii.Lamagaun–Danda. It is the only trail to Danda, so closing it leaves Danda with no route at all. Every other trail lies on a loop (Ward office, Deurali, Phedi, Simle; Ward office, Simle, Pipalbot, Thulogaun; Simle, Phedi, Lamagaun, Pipalbot), so when one of them is closed, the places it joined can still be reached the other way round the loop.

• i.The members who play volleyball or karate, in alphabetical order: Bishal Limbu, Dikshya Karki, Ekta Basnet, Jenish Shrestha.
• ii.5, 3. COUNT(*) counts every row; COUNT(paid_on) counts only the rows where paid_on isn’t NULL, the three paid fees.

iii. Every member whose fee isn’t paid, in alphabetical order. Ekta has no fee row at all, so the LEFT JOIN keeps her with paid_on filled in as NULL:

iv. A plain JOIN keeps only members who have a matching row in fees. Ekta has none, so she would be dropped before the WHERE is checked, and the list would show only Bishal and Jenish. A LEFT JOIN keeps every row of the first table, members, matched or not.

• i.To a computer, text must match exactly. “Annapurna” and “annapurna ” (small a, with a space at the end) are different values, and so are “Dhaulagiri” and “DHAULAGIRI”, and “Manaslu” and the misspelling “Manasulu”. So it counts six different houses.
• ii..str.strip() takes the space off the end, and .str.title() makes the first letter capital and the rest small: both become Annapurna and Dhaulagiri. But “Manasulu” is a different spelling, not a matter of spaces or capitals, so it needs replace, with the dictionary saying what it should become.
• iii.It removes rows that are exactly the same as an earlier row: Bipin signed up twice, so his second row goes. (After cleaning, the two rows are identical in every column.)
• iv.Each house now has two students:

houseAnnapurna     2Dhaulagiri    2Manaslu       2Name: count, dtype: int64

• i.Sense (the sensor measures the tank’s level), connect (the Wi-Fi sends the readings), process (a program decides what the readings mean) and act (the pump is switched on, or the caretaker is told).
• ii.An actuator is a part that does something in the physical world when the computer tells it to. Here it is the pump (or the switch that turns it on).
• iii.Factory usernames and passwords are the same on thousands of devices and are published, so anyone can log in to a device that still has them. In 2016 the program Mirai took over about a hundred thousand cameras and routers just by trying such passwords.
• iv.Any one: it keeps working when the Wi-Fi or internet is down; it acts at once, with no delay for the readings to go to the cloud and back; it doesn’t depend on the company’s service still running (or being paid for).

"""The sweet shop's Tihar offer.""" BOX_PRICE = 450      # rupeesBIG_ORDER = 5000     # rupees: from here, Rs 200 offBIG_ORDER_OFF = 200  def price(boxes):    """The price in rupees of this many boxes: every 4th box free,    and Rs 200 off if that still costs Rs 5,000 or more."""    free = boxes // 4    cost = (boxes - free) * BOX_PRICE    if cost >= BIG_ORDER:        cost = cost - BIG_ORDER_OFF    return cost  if __name__ == "__main__":    # tests at the edges: the 4th box, and either side of Rs 5,000    print(price(3), "should be 1350")    print(price(4), "should be 1350")    print(price(5), "should be 1800")    print(price(14), "should be 4950")    print(price(16), "should be 5200")

Run by itself, sweets.py prints its tests:

1350 should be 13501350 should be 13501800 should be 18004950 should be 49505200 should be 5200

import sweets total = 0for customer in range(1, 4):    boxes = int(input(f"Customer {customer}: how many boxes? "))    cost = sweets.price(boxes)    print("Price: Rs", cost)    total = total + costprint("Today's total: Rs", total)

Customer 1: how many boxes? 4Price: Rs 1350Customer 2: how many boxes? 7Price: Rs 2700Customer 3: how many boxes? 15Price: Rs 5200Today's total: Rs 9250

4 boxes: 1 free, 3 paid, Rs 1,350. 7 boxes: 1 free, 6 paid, Rs 2,700. 15 boxes: 3 free, 12 paid, Rs 5,400, which is Rs 5,000 or more, so Rs 5,200. Together Rs 9,250.

The same program, with these three lines in place of the last one:

import sqlite3 db = sqlite3.connect(":memory:")db.execute("CREATE TABLE items (item_id INTEGER PRIMARY KEY, name TEXT, kind TEXT, price INTEGER)")db.execute("""CREATE TABLE sales (sale_id INTEGER PRIMARY KEY,              item_id INTEGER REFERENCES items(item_id),              day TEXT, quantity INTEGER)""")db.executemany("INSERT INTO items VALUES (?, ?, ?, ?)", [    (1, "Laddu box", "sweet", 450),    (2, "Barfi box", "sweet", 600),    (3, "Diyo, pack of 12", "lamp", 120),    (4, "Marigold garland", "flower", 80),    (5, "Candles, pack of 10", "lamp", 150),    (6, "Jeri, 1 kg", "sweet", 380),])db.executemany("INSERT INTO sales VALUES (?, ?, ?, ?)", [    (1, 3, "Kag Tihar", 14),    (2, 4, "Kag Tihar", 20),    (3, 1, "Kukur Tihar", 6),    (4, 4, "Kukur Tihar", 35),    (5, 3, "Laxmi Puja", 40),    (6, 4, "Laxmi Puja", 60),    (7, 2, "Laxmi Puja", 9),    (8, 6, "Laxmi Puja", 12),    (9, 5, "Laxmi Puja", 25),])  def ask(sql):    """Print each row the query gives, then a blank line."""    for row in db.execute(sql):        print(row)    print()  ask("SELECT name, price FROM items WHERE kind = 'sweet' AND price < 500 ORDER BY price")ask("SELECT day, SUM(quantity) FROM sales GROUP BY day")ask("""SELECT items.name, sales.quantity FROM sales       JOIN items ON sales.item_id = items.item_id       WHERE sales.day = 'Laxmi Puja' ORDER BY sales.quantity DESC""")

('Jeri, 1 kg', 380)('Laddu box', 450) ('Kag Tihar', 34)('Kukur Tihar', 41)('Laxmi Puja', 146) ('Marigold garland', 60)('Diyo, pack of 12', 40)('Candles, pack of 10', 25)('Jeri, 1 kg', 12)('Barfi box', 9)

(The sales are made up for this paper.)

mela = {    "Main gate": ["Parking", "Food stalls", "Ferris wheel"],    "Parking": ["Main gate"],    "Food stalls": ["Main gate", "Stage", "Toilets"],    "Ferris wheel": ["Main gate", "Swings"],    "Swings": ["Ferris wheel", "Stage"],    "Stage": ["Food stalls", "Swings", "Help desk"],    "Toilets": ["Food stalls", "Help desk"],    "Help desk": ["Stage", "Toilets"],    "Fireworks area": [],}  def fewest_steps(graph, start, goal):    """The route from start to goal with the fewest steps, or None."""    came_from = {start: None}    to_visit = [start]    while len(to_visit) > 0:        place = to_visit.pop(0)        if place == goal:            route = []            while place is not None:                route.append(place)                place = came_from[place]            route.reverse()            return route        for nxt in graph[place]:            if nxt not in came_from:                came_from[nxt] = place                to_visit.append(nxt)    return None  for start in ["Swings", "Parking", "Fireworks area"]:    route = fewest_steps(mela, start, "Help desk")    if route is None:        print(start, "to Help desk: No way")    else:        print(start, "to Help desk:", " → ".join(route), "(" + str(len(route) - 1), "paths)")

Swings to Help desk: Swings → Stage → Help desk (2 paths)Parking to Help desk: Parking → Main gate → Food stalls → Stage → Help desk (4 paths)Fireworks area to Help desk: No way

From the Parking, the way through the Toilets is also 4 paths: any route of 4 is right.

• i.// divides and keeps only the whole number: the number of complete groups of 4 boxes, which is the number of free boxes (15 // 4 is 3). 14 boxes cost Rs 4,950 and 16 boxes Rs 5,400 before the Rs 200 off, so they test both sides of the Rs 5,000 edge, where mistakes such as > instead of >=, or taking the Rs 200 off before the free boxes, show up.
• ii.It makes one group for each day, and SUM(quantity) adds up the quantity within each group, so there is one row per day. Without it, all the rows are one group: a single row, the total for the whole festival, 221.
• iii.So that no place is added to the list twice. Stage, for example, is next to both the Food stalls and the Swings; if it were marked only when visited, it would be added once from each and visited twice, which wastes work. Marking it when it is first added also keeps the note of where it was first reached from, which is on a route with the fewest paths.