Pre-released Material for June 2015 Final

5/21/2015

Prepared By: | Tanvir Iqbal Khan

O’ LEVEL

COMPUTER

SCIENCE

2210

PRACTICE PAPER OF

PRE-RELEASED MATERIAL 2015

Pag

e1

SYLLABUS CODE: 22101/01

O’ LEVEL COMPUTER SCIENCE

Author: Tanvir Iqbal Khan Subject Specialist – O’ Level Computer Science

A’ Level Computing

Website: sirtanviriqbalkhan.tk Facebook: www.facebook.com/tanvirik

Email: [email protected] PHONE: +923212490887

You are advised to spend no longer than 40 minutes answering this section. Here is a copy of the pre-release material. DO NOT attempt Tasks 1, 2 and 3 now. Use the pre-release material and your experience from attempting the tasks before the examination to answer Section A Question 1.

TASK 1

A school keeps records of the weights of each pupil. The weight, in kilograms, of each pupil is

recorded on the first day of term. Input and store the weights and names recorded for a class of

30 pupils.

You must store the weights in a one-dimensional array and the names in another one-

dimensional array.

All the weights must be validated on entry and any invalid weights rejected. You must decide

your own validation rules. You may assume that the pupil’s names are unique. Ouput the names

and weights of the pupils in the class.

TASK 2

The weight, in kilograms, of each pupil is recorded again on the last day of term. Calculate and

store the difference in weight for each pupil.

TASK 3

For those pupils who have a difference in weight of more than 2.5 kilograms, output, with a

suitable message, the pupil’s name, the difference in weight and whether this is a rise or fall.

Your program must include appropriate prompts for the entry of data. Error messages and other

outputs need to be set out clearly and understandably. All variables, constants and other

identifiers must have meaningful names. Each task must be fully tested.

Pag

e2







O’ LEVEL COMPUTER SCIENCE CIE EXAM 2015

PRE-RELEASED MATERIAL: PAPER 2

SOLUTION: Algorithm

1. Set Name = “ “

2. Set NameCount = 0

3. Set WeightFirstDay = 0

4. Set WeightCountFirstDay = 0

5. Set WeightLastDay = 0

6. Set WeightCountLastDay = 0

7. Set WeightDifference = 0

8. Set WeightDifferenceCount = 0

9. For PupilCount = 1 to 30

10. Print “Enter Pupil’s Name”

11. Input Name “ “

12. NameCount(PupilCount) = Name

13. Print “Pupil’s First day weight”

14. Input WeightFirstDay

15. If WeightFirstDay > 15 AND WeightFirstDay < 100 Then

16. WeightCountFirstDay (PupilCount) = WeightFirstDay

17. Else

18. Print “Invalid Weight”

19. Input WeightFirstDay

20. WeightCountFirstDay (PupilCount) = WeightFirstDay

21. End If

22. Next PupilCount

Initialization of Variables

Loop for First Day Name & Weight if 30 Students

Data Validation for Invalid Weight

Pag

e3







23. For PupilCount = 1 to 30

24. Print “Enter Pupil’s last day weight"

25. Input WeightLastDay

26. WeightCountLastDay (PupilCount) = WeightLastDay

27. WeightDifference = WeightLastDay (PupilCount) – WeightCountFirstDay (PupilCount)

28. WeightDifferenceCount (PupilCount) = WeightDifference

29. If WeightDifferenceCount (PupilCount) > 2.5 Then

30. Print NameCount (PupilCount), WeightDifferenceCount (PupilCount), “Rise in Weight”

31. Else if WeightCountLastDay(PupilCount) < WeightCountFirstDay (PupilCount)

32. Print NameCount (PupilCount), WeightDifferenceCount (PupilCount), “Fall in Weight”

33. Else If WeightDifference = 0 or WeightDifference < 2.5 Then

34. Print NameCount (PupilCount), WeightCountFirstDay (PupilCount)

35. End If

36. Next PupilCount

Loop For Input Weight For Last Day

Equation is used to calculate Weight Difference between First Day & Last Day

Data Validation For Weight Difference if more than 2.5 Kilogram

Display appropriate message along with Name & Weight Difference if Weight Difference is

found more than 2.5 Kilogram on last day

Display Students’ Name whose Weight difference is same as First Day

Pag

e4







SOLUTION: Programming Language (Visual Basic 6.0)

Dim StudentName(1 To 3) As String Dim StudentWeight(1 To 3) As Single Dim WeightDifference(1 To 3) As Single Dim STName As String Dim count, Weight, Difference, PreviousWeight As Single STName = "" count = 0 Weight = 0 Difference = 0 PreviousWeight = 0

For count = 1 To 30 STName = InputBox("Enter Student Name", "First day of the term") StudentName(count) = STName Weight = InputBox("Enter Student Weight in KG", "First day of the term")

If Weight > 10 And Weight <= 100 Then StudentWeight(count) = Weight Else MsgBox "Invalid Weight " Weight = InputBox("Enter Valid Student Weight in KG", "First day of the term") StudentWeight(count) = Weight End If Next count

For count = 1 To 30 MsgBox StudentName(count) & " " & StudentWeight(count), , "First day of the term" Next count

Declaration of Variables

Initialization of Variables

Input Students Name and Weight in One Dimensional Array on First Day of the Term for 30

Students

Validation check to restrict invalid Weight

Output all students’ Name and Weight from First Day of the Term

Pag

e5







For count = 1 To 30

PreviousWeight = StudentWeight(count)

Weight = InputBox("Enter Student Weight in KG", "Last day of the term") StudentWeight(count) = Weight

Difference = Val(StudentWeight(count)) - Val(PreviousWeight) WeightDifference(count) = Difference

If Val(WeightDifference(count)) >= 2.5 Then MsgBox StudentName(count) & " has gained " & WeightDifference(count) & "KG", , "Last day of the term" ElseIf Val(WeightDifference(count)) <= -2.5 Then

MsgBox StudentName(count) & " has lost " & WeightDifference(count) * -1 & "KG", , "Last day of the term" End If Next count

Input Students’ Weight for Last Day of the Term

Calculate Difference between Fist Day Weight and Last Day Weight of the Term

Validation Check if the Difference is 2.5 Kg or above

Remove minus value of Difference to make result Positive

Pag

e6







1. (a) All variables, constants and other identifiers should have meaningful names.

(i) Declare the array to store the students’ names.

...............................................................................................................................

(ii) Declare the arrays to store each student’s weight and weight difference.

............................................................................................................................. ..

...............................................................................................................................

(b) (i) Show the design of your algorithm to complete Task 1 and Task 2 using pseudocode, programming statements or a flowchart. Do not include any of the validation checks in your algorithm. ............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

....................................................................................................................................

For Examiner’s

Use

[8]

Pag

e7







(ii) Comment on the efficiency of your design.

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

(c) Show two different sets of student data that you could use to check the validation

used in Task 1. Explain why you chose each data set.

Set 1.............................................................................................................................

Reason for choice.........................................................................................................

............................................................................................................................. .......

....................................................................................................................................

Set 2.............................................................................................................................

Reason for choice.........................................................................................................

............................................................................................................................. .......

....................................................................................................................................

Pag

e8







(d) (i) Explain how you select the student with the “Weight rise” or “Weight fall” (Task 3).

You may include pseudocode or programming statements to help illustrate your

explanation.

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

............................................................................................................................. .......

(ii) How does your program work when there is weight of a student having no change? Explain using your method given in part (d)(i).

............................................................................................................................. .......

....................................................................................................................................

............................................................................................................................. .......

Pag

e9







2. A golf course charges $10 for each game of two people. Each additional person incurs a

further charge of $2 per game. If they book two or more games in advance, they get a

10% discount on the total charge.

The following program has been written in pseudocode to calculate the charges for a

game.

1 extracost = 0

2 input numberpeople, numbergames

3 charge = 10 * numbergames

4 extrapeople = numberpeople – 2

5 if numberpeople < 2 then extracost = 2 * extrapeople * numbergames

6 charge = extracost

7 if numbergames > 1 then charge = charge * 0.1

8 print charge

There are three errors in the program. Locate these errors and suggest a correct piece

of coding.

Error 1..........................................................................................................................

....................................................................................................................................

Correction 1..................................................................................................................

....................................................................................................................................

Error 2..........................................................................................................................

....................................................................................................................................

Correction 2..................................................................................................................

....................................................................................................................................

Error 2..........................................................................................................................

....................................................................................................................................

Correction 2..................................................................................................................

....................................................................................................................................

(b) What type of validation check is being carried in line number 5 and 7?

....................................................................................................................................

Pag

e10







3. (a) The following pseudocode was written to input 1000 dates.

1 count = 1

2 repeat

3 input day, month, year

4 count = count + 1

5 until count = 1000

(i) Describe why the loop only inputs 999 dates instead of 1000.

.....................................................................................................................

.....................................................................................................................

.................................................................................................................. [1]

(ii) What needs to be changed or added to the above code to make sure 1000

dates are input?

.....................................................................................................................

.....................................................................................................................

.................................................................................................................. [1]

(b) Errors in code can be found using test data.

Name three different types of test data. Using month from the pseudocode above,

give an example of each type of test data.

test data type 1………………………………………………………………………..……………………………..

example …………….…………………………………………………………………..……………………………..

……………………………………………………………………………………….……..……………………………..

test data type 2………………………………………………………………………..……………………………..

example …………….…………………………………………………………………..……………………………..

……………………………………………………………………………………….……..……………………………..

test data type 3………………………………………………………………………..……………………………..

example …………….…………………………………………………………………..……………………………..

……………………………………………………………………………………….……..………………………… [6]

Pag

e11







4. A piece of pseudocode was written to input 1000 positive numbers and then output the

highest and lowest numbers.

10 highest = 0

20 lowest = 0

30 for count = 1 to 100

40 input number

50 if number > highest then number = highest

60 if number < lowest then number = lowest

70 count = count + 1

80 next count

90 print highest, lowest

There are errors in the code.

Locate these errors and suggest a correction.

Error 1……………………………………………………………………………………………………………………..

……………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

Correction……………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

Error 2……………………………………………………………………………………………………………………..

……………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

Correction……………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

Error 3……………………………………………………………………………………………………………………..

Pag

e12







……………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

Correction……………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

Error 4……………………………………………………………………………………………………………………..

……………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

Correction……………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………[8]

Pag

e13







5. The following flowchart inputs ten temperatures and outputs the average (mean)

temperature and the number of temperatures which were negative (i.e. < 0).

Pag

e14







(a) Complete the trace table for this flowchart using the following test data:

5, 11, 16, -4, -10, 8, 10, -3, 17, 10

(b) What values are outputs from the flowchart using the above test data?

………………………………………………………………………………….….[1]

Pag

e15







6. A floor turtle uses the following commands:

In the following grid, each of the squares represents 10 cm by 10 cm:

Pag

e16







Complete the set of instructions to draw the shape shown on the left:

1 PENDOWN

2 LEFT 90

3 REPEAT 2

4 ……………………………………………………………………

5 ……………………………………………………………………

6 ……………………………………………………………………

7 ……………………………………………………………………

8 ……………………………………………………………………

9 ……………………………………………………………………

10 …………………………………………………………………

11 …………………………………………………………………

12 …………………………………………………………………

13 …………………………………………………………………

14 …………………………………………………………………

15 …………………………………………………………………

16 …………………………………………………………………

17 …………………………………………………………………

18 …………………………………………………………………

19 …………………………………………………………………

20 …………………………………………………………………

21 …………………………………………………………………

22 …………………………………………………………………

23 …………………………………………………………………

24 …………………………………………………………………

25 …………………………………………………………………

[6]

Pag

e17







7. A shop keeps its stock file on a computer system. Part of the file is shown in the diagram

below:

The following codes have been used.

B = Black G = Green R = Red S = Silver

(a) State how many records are shown in the diagram.

.............................................................................................................................................. [1]

(b) State two advantages of coding the data in the COLOUR field.

1. ...............................................................................................................................................

…………………………………………………………………………………………………………………………………………

2. ……………………………………………………………………………………………………..…………………………………

…………………………………………………………………….………………………………………………………………[2]

(c) State the data type that should be used for the WEIGHT (KG) data.

................................................................................................................................................[1]

(d) State one advantage of using fixed-length records for storing the data.

...............................................................................................................................................[1]

(e) Which STOCK NO data will be listed if the following search condition is input?

(COLOUR NOT “B”) AND (WEIGHT (KG) < 2.0)

......................................................................................................................................................[2]

Pag

e18







(f) Write down a search condition that will search for all the items with less than 16 in

stock and the price is more than $100.

..................................................................................................................................................... [3]

(g) State which field should be used to link this stock file to a supplier file. Give a reason

for your choice of field.

Field..................................................................................................................................................

Reason.............................................................................................................................................

......................................................................................................................................................[2]

Pag

e19







VERY IMPORTANT:

Students are strongly advised to follow instructions written below.

1. Practice on each section of the algorithm of page 2 of this Pre-released material’s

‘Practice Question Paper’

2. Practice on topic ‘Program flowchart’ of Past Papers (2011 – 2014 all May and October

papers) from previous syllabus ‘Computer Studies 7010.

3. Practice on topic ‘Logo Programming’ of Past Papers (2011 – 2014 all May and October

papers) from previous syllabus ‘Computer Studies 7010.

4. Practice on topic ‘Database’ of Past Papers (2011 – 2014 all May and October papers)

from previous syllabus ‘Computer Studies 7010.

Your valued & precious feedback and suggestions are always appreciated.

GOOD LUCK!

Sir Tanvir Khan

Pre-released Material for June 2015 Final

Documents

day weight

pupils names

level computing website

print pupils

input weightfirstday

invalid weights

weightcountfirstday

day of term