4.1. Algorithms
A subsection of Information Technology, 9626, through 4. Algorithms and flowcharts
Listing 10 of 10 questions
A programmer is writing an algorithm in pseudocode to represent a company’s payroll system. The system calculates a worker’s wages before tax by multiplying the number of hours worked by the rate of pay per hour. A procedure within the main algorithm representing this could be: PROCEDURE BeforeTax(Hours, Rate) WagesBeforeTax Hours * Rate ENDPROCEDURE There are two stages involved in calculating the wages after tax: • the amount of tax paid by the worker is calculated by multiplying the WagesBeforeTax by the rate of tax (35%); • the amount of tax paid is then subtracted from the WagesBeforeTax. Write a procedure for calculating the wages after tax, assuming the value of WagesBeforeTax is passed to it. The programmer’s algorithm will use the BeforeTax() procedure and the procedure created in part to calculate and output the wage after tax for each worker. Complete the algorithm. The statements have been numbered to help you. count INPUT NumberOfWorkers REPEAT UNTIL
9626_w22_qp_12
THEORY
2022
Paper 1, Variant 2
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A teacher wishes to produce a computer program to output the grades awarded for all of her students. If a student scores: • more than 60 marks, they are awarded a grade A • 50 – 60 marks, they are awarded a grade B • 40 – 49 marks, they are awarded a grade C • below 40 marks, they are awarded a grade D. The teacher has written the following algorithm before writing the program. Unfortunately, there are errors and some lines have been left out . She has, however, managed to include the correct number of ELSE statements. 1. INPUT mark 2. IF mark > 60 3. THEN 4. PRINT "A" 5. ELSE 6. IF mark = 40 11. THEN 12. PRINT "C" 13. ELSE 14. PRINT "D" 15. ENDIF 16. ENDIF Identify each error or omission and how these could be corrected. Line numbers have been included to help you.
9626_w22_qp_13
THEORY
2022
Paper 1, Variant 3
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A company employs workers as: • labourers who are paid $18 per hour • office workers who are paid $22 per hour • managers who are paid $30 per hour. A computer programmer has written part of an algorithm in pseudocode. The completed algorithm will calculate and output the wage for each worker. The inputs will be: • the number of workers • the job code for each worker (L for labourer, O for office worker or M for manager) • the number of hours each worker has worked. If L, O or M is not entered for the job code then the message ‘Invalid job code’ will be output. The algorithm will terminate when all the workers’ details have been entered. It will use the CASE…ENDCASE construct to determine the rate of pay. Complete the algorithm by filling in the missing lines. INPUT number REPEAT INPUT jobcode, hours 'L' : rate count count + 1
9626_w23_qp_11
THEORY
2023
Paper 1, Variant 1
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Sukhjinder, a mathematics student, has defined a procedure using pseudocode. It calculates the area of a parallelogram by multiplying the base by the height. All parallelograms will have an area of less than 1000. The procedure Sukhjinder has written is: PROCEDURE parallelogram(base,height) area base*height ENDPROCEDURE He has also begun writing an algorithm which calls the procedure and then passes back the area. The main algorithm accepts inputs of the base and the height of 10 parallelograms, one at a time. It will output the areas of the largest and smallest parallelograms. Complete the algorithm for Sukhjinder by filling in the missing lines. count smallest WHILE count IF area ENDIF
9626_w23_qp_12
THEORY
2023
Paper 1, Variant 2
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A programmer is writing an algorithm in pseudocode to determine whether a number is a factor of another number. Y is a factor of X if the result of X/Y is a whole number. In pseudocode INT(W) returns the whole number part of W. If W is the same as INT(W) that means W is a whole number. Complete the algorithm, including the missing first line, in pseudocode. Each THEN or ELSE statement should be on a separate line to the action resulting from it. The algorithm uses: • W to store the result of X divided by Y • Z to store the value of INT(W). The algorithm must output the values of Y and X together with an appropriate message if Y is a factor of X or if Y is not a factor of X. W←X/Y Z=INT(W)
9626_w23_qp_13
THEORY
2023
Paper 1, Variant 3
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A microprocessor-controlled car park barrier is used to allow cars to enter a car park. When a car approaches the barrier, the barrier automatically rises to allow the car to enter. It does not lower until the car is safely clear of the barrier system. There is a light sensor and light beam source immediately before the barrier. No tickets are issued by the system. The system operates continuously while it is switched on. Complete this pseudocode algorithm to describe the processing involved. Your pseudocode algorithm should include IF…THEN statements. REPEAT INPUT reading from induction loop
9626_s22_qp_13
THEORY
2022
Paper 1, Variant 3
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Questions Discovered
10