Computer Science Paper 22
Oct / Nov 2016·2210·5 questions
Mock exam: 105 min, official timing
Question paper
Question 1
Question 2
Question 3
Question 4
Question 5
Mark scheme
Question 1
1(a)(i)[3]
Many correct answers, they must be meaningful. This is an example only. – Choice, integer, choice of charity – Cost, real, cost of shopping – Donation, real, donation calculated from cost of shopping [3]
1(a)(ii)[3]
– Array – a set of (similar) variables grouped together// description or array declaration applied to the scenario e.g. DonationTotals[1:3] – allows for more efficient programing e.g. use of indices//each charity total can be identified by an index or – List – a set of variables grouped together// description or list declaration applied to the scenario e.g. DonationTotals[] – allows for more efficient programing e.g. use of a loop to update each charity or – Variables – storage locations that can be changed// description or declaration applied to the scenario e.g. DonationTotal1, DonationTotal2 and DonationTotal3 – e.g. as there are only 3 charities so there is no need to use an array [3]
1(b)[5]
Any five from:
– Prompt for input of charity choice // prompt for input of value of shopping – input charity choice – check for input of 1, 2, or 3 – input value of shopping – calculate donation – add donation to the appropriate total – output name of charity and amount/total amount donated [5]
Sample Answer. REPEAT PRINT 'Please enter choice of charity 1, 2. or 3 ' INPUT Choice UNTIL Choice = 1 or Choice = 2 or Choice = 3 PRINT 'Please enter value of shopping bill ' INPUT BillValue Donation BillValue * 0.01 Total (Choice) Total (Choice) + Donation PRINT 'Charity ', CharityName (Choice), ' has received a donation of ', Donation
1(c)[6]
Maximum six marks in total for question part Description (may include reference to program statements) – when charity choice = -1 – display total donation for each charity … – … with corresponding charity name… – description of method for selecting descending order of totals – evidence that the method works – calculate grand total from 3 totals / sum of all donations – output ‘GRAND TOTAL DONATED TO CHARITY’ and grand total [6]
1(d)[3]
Any three from:
– input number of charities – store the number of charities as a variable – change the upper value of the choice input – change the array bounds for total donations etc.// add new variables to hold extra values – the need to change the code… – … to allow for differing number of charities [3]
Question 2
1 mark for identifying each error, 1 mark for the corresponding change – line 2 or Counter = 100 – Counter = 0 – line 6 or UNTIL Num < 0 – UNTIL Num >= 0 – line 7 or Total = Total + 1 – Total = Total + Num – line 8 or Counter = Counter + Num – Counter = Counter + 1 [8]
Question 3
Trace table for input value 33 X A B OUTPUT 33
Question 4
1 1 Å (1 mark) Æ (1 mark) Trace table for input value 75 X A B OUTPUT 75 9 3 3 9 1 1 1 1 1 Å (1 mark) Æ (1 mark) [4]
For each example: 1 mark for correct structure, 1 mark for appropriate content, 1 mark for the reason. There are many correct answers these are only examples IF X > 0 AND X <= 10 THEN PRINT 'In Range' ELSE PRINT 'Out of Range' ENDIF – e.g. checking a condition that may be complex//uses relational operators// checking for a range of values// only 2 options CASE X OF 1 : PRINT 'Option 1' 2 : PRINT 'Option 2' 3 : PRINT 'Option 3' OTHERWISE PRINT 'Incorrect choice' ENDCASE – e.g. checking for discrete/large number/more than 2 of values [6]
Question 5
5(a)[1]
– 6 [1]
5(b)[3]
– Play text – No Seats Stalls number – Price Stalls Seats $ currency [3]
5(c)[3]
1 mark for correct plays, 1 mark for correct dates with each play and no extra fields or text, 1 mark for the order As You Like It 01/07/2016 Julius Caesar 22/07/2016 Macbeth 14/07/2016 [3]
5(d)[5]
Field: Play Performance Date Number Seats Circle Price Circle Seats $ Table: PLAYPRODUCTION PLAYPRODUCTION PLAYPRODUCTION PLAYPRODUCTION Sort: Ascending/ Descending Show: ;
;
;
Criteria: >=6 or: (1 mark) (1 mark) (2 marks) 1 for Criteria 1 for correct Field & Table & Sort & Show & or (1 mark) [5]