A LevelComputer ScienceCambridge (CIE)Exam Questions11. ProgrammingProgramming Basics

Programming Basics (Cambridge (CIE) A Level Computer Science): Exam Questions

Exam code: 9618

33 mins8 questions
14 marks

Refer to the insert for the list of pseudocode functions and operators.

A program will calculate the tax payable based on the cost of an item.

Calculations will occur at many places in the program and these involve the use of one of three tax rates.

Tax rate values represent a percentage. For example, a tax rate value of 5.23 represents 5.23%. In this case, the tax payable on an item costing $100 would be $5.23.

Tax rate values are used at several places within the program. One example is given in pseudocode as follows:

HighRate leftwards arrow FALSE
CASE OF ItemCost
<= 50 : TaxRate leftwards arrow 3.75 // tax rate of 3.75%
<= 200 : TaxRate leftwards arrow 5.23 // tax rate of 5.23%
> 200 : TaxRate leftwards arrow 6.25 // tax rate of 6.25%
HighRate leftwards arrow TRUE
ENDCASE
TaxPayable leftwards arrow ItemCost * TaxRate // tax payable

During the design of the program, tax rate values have been used wherever they are needed as shown in the pseudocode example above. Tax rates do not change while the program runs.

(i) Identify a more appropriate way of representing the tax rate values in the final program.

[1]

(ii) Describe the benefits of your answer to part (b)(i) with reference to this program.

[3]

How did you do?

23 marks

Evaluate each expression in the table by using the data values shown in part (b).

Write ‘ERROR’ if the expression contains an error.

Expression

Evaluates to

Available AND NOT(Index > 100)

Index MOD 30

NUM_TO_STR(Index + "33")

How did you do?

3a4 marks

Refer to the insert for the list of pseudocode functions and operators.

An algorithm is developed in pseudocode before being coded in a programming language.

The following table shows four valid pseudocode assignment statements. Complete the table by giving an appropriate data type to declare each of the variables A, B, C and D.

Assignment statement

Data type

A leftwards arrowLEFT(MyName, 1)

B leftwards arrow Total * 2

C leftwards arrowINT(ItemCost) / 3

D leftwards arrow"Odd OR Even"

How did you do?

3b4 marks

Other variables in the program have example values as shown:

Variable

Value

Sorted

False

Tries

9

ID

"ZGAC001"

Complete the table by evaluating each expression, using the example values.

Expression

Evaluates to

Tries < 10 AND NOT Sorted

Tries MOD 4

TO_LOWER(MID(ID, 3, 1))

LENGTH(ID & "xx") >= Tries

How did you do?

42 marks

An algorithm has three steps. It will:

  1. repeatedly input a pair of numeric values A and B

  2. count the number of pairs that are input until A has been greater than B 10 times

  3. output the number of pairs that were input.

Step 1 of the algorithm is changed.

A variable ThisSequence is used to enter a sequence of 10 pairs of numeric values, using a single input statement.

Following the input of ThisSequence the revised algorithm will extract the pairs of numbers.

Describe the variable ThisSequence and how the numbers are extracted.

How did you do?

54 marks

Program variables have data types as follows:

Variable

Data type

MyChar

CHAR

MyString

STRING

MyInt

INTEGER

Complete the table by filling in each gap with a function (from the insert) so that each expression is valid.

Expression

MyInt leftwards arrow.......................................... (3.1415926)

MyChar leftwards arrow.......................................... ("Elwood", 3, 1)

MyString leftwards arrow....................................... ( ....................................... (27.509))

MyInt leftwards arrow....................................... ( ........................................ ("ABC123", 3))

How did you do?

64 marks

Refer to the insert for the list of pseudocode functions and operators.

Four of the expressions used in the program are represented by pseudocode in the table.

Complete each pseudocode expression with a function or operator so that it evaluates to the value shown.

Any functions and operators used must be defined in the insert.

Pseudocode expression

Evaluates to

........................................ ("Random", 2, 3)

"and"

5 + ........................................ (10/11/2023)

15

........................................ ("45000")

TRUE

(20 ........................................ 3) + 1

3

How did you do?

74 marks

Other variables in the program have example values as shown:

Variable

Example value

Total

124.00

DepRate

2.00

Description

"AB12345:Cleaning Brush (small)"

Complete the table by evaluating each expression using the example values.

Expression

Evaluates to

(Total * DepRate) + 1.5

RIGHT(Description, 7)

(LENGTH(Description) - 8) > 16

NUM_TO_STR(INT(DepRate * 10)) & '%'

How did you do?

84 marks

Other variables in the program have example values as shown:

Variable

Value

Active

TRUE

Fraction

0.2

Code

"Ab12345"

Complete the table by evaluating each expression using the example values.

Expression

Evaluates to

Fraction >= 0.2 AND NOT Active

INT((Fraction * 100) + 13.3)

STR_TO_NUM(MID(Code, 4, 2)) + 5

LENGTH("TRUE" & Code)

How did you do?