2021 CWSS Computing P2

COMMONWEALTH SECONDARY SCHOOL END OF YEAR EXAMINATION 2021 COMPUTING Paper 2 (Practical) Name: _____________________________________ ( ) Class: ___________ SECONDARY FOUR EXPRESS/5 NORMAL (ACADEMIC) Wednesday 1 Sept 2021 7155/2 0800 – 1030 2 hour 30 mins READ THESE INSTRUCTIONS FIRST Answer all questions. All tasks must be done in the computer laboratory. You are not allowed to bring in or take out any pieces of work or materials on paper or electronic media or in any other form. Programs are to be written in Python. Save your work using the file name given in the question as and when necessary. The number of marks is given in brackets [ ] at the end of each question or part question. The total number of marks for this paper is 50. Name of setter: Mrs Leong Sai Hong This paper consists of 5 printed pages including the cover page. [Turn over

2 Task 1 A food delivery company uses spreadsheet software to record each customer order. Serving sizes comes in “Small” and “Large”. Each customer is supposed to purchase only packets of food of the same serving size. You are required to finish setting up the spreadsheet to calculate the cost each customer has to pay. Open the file GOURMET.xlsx and you will see the following data. Save the file as MYGOURMET_<class>_<index_number>_<your name>.xlsx 1. In cells F4 to F21 enter a formula that uses an appropriate function to search for the Packing Charges in the Packing Charges by Number of Packets table. Use it to calculate the Packing Fees for each order. (E.g. a customer who orders between 1 and 4 packs will be charged $0.50 for his order.) [2] 2. Use a conditional statement to identify whether a discount is to be given. For customers who order large serving or where the number of packets is greater than 15, put Yes in the Discount column. [2] 3. Use a conditional statement to calculate the total cost in the Total Cost column. Customer who are identified as Yes for the Discount must be given a 5% reduction for the total cost. [2]

3 4. In cell F25 and F26, enter a formula that uses an appropriate function to count the number of small and large packets of food sold. [2] 5. In cell A4 to H21, use a formatting tool to change the colour of the row to yellow if the Unit Cost is greater than $10. [2] Task 2 The following program allows the user five chances to search for characters within a string. text = "With great power comes great responsibility" chances = 5 for c in range(chances): ch = input("Search character:") for t in text: if ch == t: break Open the file SEARCH.py Save the file as MYSEARCH_<class>_<index_number>_<your name>.py 6. Edit the program so that: (a) For each character that searched, it outputs a suitable message only once at the end of the search if the character is not found in the string. [3] (b) It concatenates all characters that are not found in the string and outputs this new string. [3] 7. Save your program as VARSEARCH_<class>_<index number>_<your name>.py Edit your program so that: (a) For each character that is searched, it prints out the number of times it is found in the text. [3] (b) It works for any number of chances to search for characters. [1] Save your program.

4 Task 3 The Average Subject Grade (ASG) is used to measure a student’s overall performance. For each subject, ASG is a number between 1 and 4. The following calculates the ASG using the following rules: • Convert each subject’s score into the grade points using the table below. • Add up all the grade points. • Divide the result by the number of subjects. • Round the result to two decimal places. This will be the student’s ASG. • For example, if a student takes 7 subjects and his scores are 20, 50, 48, 79, 90, 52, 61, his corresponding ASG will be 2.57. Score Grade Grade points 70 - 100 A1 1 60 - 69 B2 2 50 - 59 C3 3 Less than 50 D4 4 There are several syntax errors and logical errors in the program. grade = ['A1','B2','C3','D4'] total=0 num = int(input("Enter number of subjects:")) score = ['']*num result=[0]*num for i in range(num): score=int(input("Enter mark:")) for i in range(len(grade)): if score[i]>70: result[0]=result[0]+1 elif score[i]>=60: result[1]=result[1]+1 elif score[i]<=50: result[2]=result[2]+1 else: result[3]=result[3]+1 for i in range(len(grade)): total=int(grade[i][:1])*result[i] print('ASG is',total) Open the file ASG.py Save the file MYASG_<class>_<index number>_<your name>.py 8. Identify and correct the errors in the program so that it works correctly according to the rules above. [10] Save your program.

5 Task 4 You have been asked to create a guessing game program. The program should: • Allow player 1 to input a 4-digit number for player 2 to guess. There must be validation present to check that the input is a 4-digit number. Output a suitable error message if validation test fails. • Allow player 2 to have 5 chances to correctly guess the number input by player 1. • When player 2 inputs the same number as player, output the number of guesses and the game ends. E.g. “You guessed correctly in 3 guess(es).” when player 2 guessed the correct number on the 3rd guess. • Output “You did not guess the correct number.” When player 2 does not input the same number as player 1. • Output “Game over!” when the player has made 5 incorrect guesses. 9. Write your program and test that it works. [8] Save your program as MYSTAR1_<class>_<index number>_<your name>.py 10. When your program is working, use the following test data to show your test result. • Test 1 – Player 1 inputs abcd • Test 2 – Player 1 inputs 5 • Test 3 – Player 1 inputs 1234 and player 2 guesses 9934 and 1234 Take a screenshot of your result and save it as TEST123_<class>_<index number>_<your name> [4] Save your file in either .jpg or .png format. 11. Save your program as MYSTAR2_<class>_<index number>_<your name>.py Extend your program as follows: • Generate the 4-digit random number where al the digits are different. Use the randint() function below: import random print(random.randint(0,9)) # outputs a random number between 0 and 9 • When the player inputs a number that does not match the generated number, output the number of “stars” which are digits found in the generated number in the correct position and the number of “moons” which are the digits found in the generated number but in the wrong position. For example, if the generated number is 2678, a guess of 2806 will result in “1 star and 2 moons”. [5] Save your program. 12. Save your program as MYSTAR3_<class>_<index number>_<your name>.py Extend your program to calculate and output the average number of stars at the end of the game. [3] Save your program. END OF PAPER