Final Exam Model Paper 5

The empty string: a string with no characters in it. It is still a string.

Decomposition: for the fair’s program, for example, one function for the stalls’ bills, one for the raffle and one for the scores.

The camera sets its brightness for the bright window, so the face, much darker than the window, comes out almost black. She should stand so the light falls on his face: the window behind her or to one side, not behind him.

The board works on 3 to 5 volts. The mains, at 230 volts, can kill and start fires. Anything on the mains must use a relay module made for it, built and checked by an adult who knows electrical work.

Half a minute: 10.4 ÷ 2 = about 5.2 GB. (A phone saves it far smaller, because one frame is usually almost the same as the one before.)

50 isn’t a multiple of 3, so pieces goes 47, 44 … 5, 2, −1, −4 … and is never exactly 0: pieces != 0 stays True forever. The condition should be while pieces > 0:.

Not a good choice. Every picture is made by computers in a data center, using electricity (often from coal and gas) and water to cool them, and a picture costs much more than a short text answer: 30 versions cost 30 times as much. A clear prompt and two or three versions, or the students’ own drawing, would do.

• i.Line 1 opens two brackets, after int and after input, but closes only one. A second ) is needed at the end of line 1: stalls = int(input("How many stalls? ")).
• ii.The inner one, input(), runs first: it asks the question and gives back what was typed, as a string, such as "12". Then int() turns that string into the whole number 12, which is put into stalls.

i. 47 % 2 is 1, so 1 == 0 is False; 128 % 2 is 0, so it prints True:

Ticket number: 47False

Ticket number: 128True

ii. The last digit of a number is its remainder when divided by 10:

ticket = int(input("Ticket number: "))print(ticket % 10 == 5)

Ticket number: 235True

i.

Sold out!15 left

ii. return ends the function at once, giving back its value. In the first call, sold == made is true, so the function returns “Sold out!” from line 3, and line 4 never runs.

def league_points(won, drawn):    return won * 3 + drawn print("Khotang House:", league_points(4, 2))print("Bhojpur House:", league_points(3, 5))

Khotang House: 14Bhojpur House: 14

Both teams have 14 points.

• i.No, not without the permission of whoever owns the song: being on YouTube doesn’t give anyone the right to use it, and a video posted online is shared with the whole world. They could use music licensed CC0, CC BY or CC BY-SA (credited), or music they make or record themselves.
• ii.No. ND means no changes, and putting music in time with moving pictures always counts as a changed version. A song under CC BY-ND may be shared as it is, but not used as a soundtrack.

• i.About 524 Hz (the note C5, more exactly 523 Hz): going up one octave doubles the frequency, 2 × 262.
• ii.262 is the frequency in hertz: the speaker moves back and forth 262 times a second. 500 is how long the note lasts, in milliseconds: half a second.

Any two:

• Informed: you know what will be collected, what for, and who will get it.
• Free: you could have said no without being punished or shut out.
• Specific: it is for a stated purpose, not “any purpose”.
• Can be taken back: you can change your mind later and withdraw it.

Her friend is wrong. Running without an error says nothing about whether the answer is right: this program prints Lowest day: 610, which is the highest day. Sunita should work out the right answer herself first (300), then run the program and compare, and test it with other lists whose answers she knows. (The fix: start with best = sales[0] and keep a smaller value with if s < best.)

i.

big = 0small = 0for player in range(1, 5):    hits = 0    for throw in range(1, 4):        result = input(f"Player {player}, throw {throw}: hit or miss? ")        if result == "hit":            hits = hits + 1    if hits == 3:        print("Big prize!")        big = big + 1    elif hits == 2:        print("Small prize!")        small = small + 1    else:        print("Better luck next time!")print("Big prizes:", big)print("Small prizes:", small)

For players who throw hit-hit-hit, hit-miss-hit, miss-miss-hit and hit-hit-hit:

Player 1, throw 1: hit or miss? hitPlayer 1, throw 2: hit or miss? hitPlayer 1, throw 3: hit or miss? hitBig prize!Player 2, throw 1: hit or miss? hitPlayer 2, throw 2: hit or miss? missPlayer 2, throw 3: hit or miss? hitSmall prize!Player 3, throw 1: hit or miss? missPlayer 3, throw 2: hit or miss? missPlayer 3, throw 3: hit or miss? hitBetter luck next time!Player 4, throw 1: hit or miss? hitPlayer 4, throw 2: hit or miss? hitPlayer 4, throw 3: hit or miss? hitBig prize!Big prizes: 2Small prizes: 1

ii. Inside the outer loop, before the inner one, so that each player starts from 0 hits. Before both loops, the hits of all the players would be added together; inside the inner loop, it would be set back to 0 at every throw.

• i.It compares the numbers from position 0: 342, 517, 128, 905, 263, 771, 450. It is found at position 6, after 7 comparisons.
• ii.300 isn’t in the list, so it compares all 12 numbers, reaches the end, and reports that it is not found.
• iii.Binary search works only on a sorted list: it throws away the half where the number can’t be, which is true only when the numbers are in order. This list is in the order the tickets were found, so binary search might wrongly say a ticket isn’t there.

• i.The school’s name, for example alt="Shree Bhojpur Secondary School": a logo’s alt text is the name it stands for, not the word “logo”.
• ii.A heading says “a new part starts here”. Screen readers, search engines and browsers use the headings as the page’s outline: a blind visitor’s screen reader lists them, so they can jump straight to “Stalls”. Bold text in a paragraph only looks like a heading; to those programs it is an ordinary paragraph.
• iii.11 px is too small to read easily, especially on a phone; body text should be about 16 px.
• iv.Give a person who hasn’t seen the page a task (“Find out when the fair is”), watch quietly without helping, and note where they hesitate or get stuck; then improve the page and test again.

• i.Updates fix security holes and problems found since the phone was made, so the phone is safest before anything else is put on it.
• ii.A phone with no lock gives every app and every account to whoever picks it up.
• iii.With two-step login, her password alone isn’t enough to sign in: a code sent to her phone (or a tap on it) is needed too. So someone who guesses or steals her password still can’t get into her account.
• iv.So that her photos and contacts are kept in a second place: if the phone is lost, stolen or broken, they aren’t lost with it, and a new phone can be set up from the backup.

a = 0b = 0while a < 5 and b < 5:    point = input("Who won the point, A or B? ")    if point == "A":        a = a + 1    elif point == "B":        b = b + 1    else:        print("Type A or B.")    print("Score:", a, "-", b)if a == 5:    print("Player A wins the game!")else:    print("Player B wins the game!")

Who won the point, A or B? AScore: 1 - 0Who won the point, A or B? BScore: 1 - 1Who won the point, A or B? AScore: 2 - 1Who won the point, A or B? AScore: 3 - 1Who won the point, A or B? CType A or B.Score: 3 - 1Who won the point, A or B? BScore: 3 - 2Who won the point, A or B? AScore: 4 - 2Who won the point, A or B? AScore: 5 - 2Player A wins the game!

A while loop fits, because nobody knows how many points the game will take. Other wordings of the messages are fine.

i. and ii. An IndentationError, on line 3:

  File "main.py", line 3    left = made - soldIndentationError: unexpected indent

Line 3 starts with spaces, but it isn’t inside an if or a loop, so it shouldn’t be indented: in Python, spaces at the start of a line mean something. Python finds this before running anything, so no question was asked.

iii. Remove the spaces at the start of line 3:

made = int(input("Sel roti made today: "))sold = int(input("Sel roti sold: "))left = made - soldprint("Left over:", left)

Sel roti made today: 100Sel roti sold: 85Left over: 15

iv.

One good page (yours will be different):

<!DOCTYPE html><html lang="en">  <head>    <meta charset="utf-8">    <meta name="viewport" content="width=device-width, initial-scale=1">    <title>Grade 8’s Sel Roti Stall</title>    <link rel="stylesheet" href="style.css">  </head>  <body>    <h1>Grade 8’s Sel Roti Stall</h1>    <p>Sel roti is a sweet, ring-shaped bread of rice flour, fried at home for Tihar. Ours is fried fresh at the fair.</p>    <h2>What we sell</h2>    <ul>      <li>Sel roti: Rs 20 a piece</li>      <li>Milk tea: Rs 25 a cup</li>      <li>Aloo achar: Rs 30 a plate</li>    </ul>    <img src="sel-roti.jpg" alt="A stack of three golden-brown sel roti rings on a plate">  </body></html>

body {  font-family: sans-serif;} h1 {  color: #8b4513;} img {  max-width: 100%;}

The max-width: 100% rule keeps the photo inside a phone’s screen.

• i.Inside the loop, the program would print a line after every point, while nobody has won yet. The loop ends only when a player has 5 points, so after it the game is over, and the winner is printed once. The program knows who won by checking which score is 5: if a == 5, A won; otherwise B did.
• ii.The spaces show which lines are inside a block: an if, an elif or a loop. For example, a = a + 1 is indented under if point == "A":, so it runs only when A won the point; and every line of the game is indented under the while, so it repeats for each point.
• iii.When the information is in rows and columns, for example each item with its price and its size, or prices for a small and a big plate. A table’s heading cells (<th>) also let a screen reader say which column a value is in, such as “Price: Rs 20”. For three items with one price each, a list is fine.