Computer Science Paper 23
Oct / Nov 2016·2210·6 questions
Mock exam: 105 min, official timing
Question paper
Question 1
Question 2
Question 3
Question 4
Question 5
Question 6
Mark scheme
Question 1
1(a)[8]
Many correct answers, the identifiers must be meaningful. These are examples only. There are two marks available for each identifier:
1(b)[4]
Any four from:
– prompt for input of candidate number – input of candidate number – check for candidate number of 1, 2 or 3 – output ‘invalid vote’ if input not 1, 2, or 3 – otherwise add 1 to appropriate total and … – … output name of candidate voted for [4]
1(c)[6]
Description (may include reference to programming statements) any six marks from – output total and … – … corresponding candidate name... – description of method for selecting descending order of totals – evidence that the method works – check if highest number of votes is a unique value – if unique output the candidate name and ‘NEW CLASS CAPTAIN’ – otherwise output ‘NO OVERALL WINNER’ [6]
1(d)[2]
Accept any reasonable suggestion(s), two marks can be awarded for either a suggestion with an accompanying description e.g. – re run the voting (1)
without the least popular candidate (1)
or accept two different suggestions e.g. – re run the voting – give the teacher the casting vote. [2]
Question 2
2(a)[4]
1 mark for each change – Line 2: OutRange = 0 – Line 6: should be OutRange = OutRange + 1 – Line 7: not needed – Line 8: NEXT X should be NEXT Count / Line 3: FOR Count = 1 TO 10 should be FOR X = 1 TO 10 [4]
2(b)[4]
Number Within range (9)
Outside range (9)
Reason 10 9 Range greater than 10, so 10 not included ………………………………………………………… 20 9 Range less than 20, so 20 not included ………………………………………………………… [4]
Question 3
Price Change Dollars TenCents OUTPUT 6.29 3.71 0.71 3 dollars 0.21 One 50 cent coin 2 2 ten cent coins One 5 cent coin (1 mark per correct column) [5]
Question 4
1 mark for each correct link up to maximum of 3 marks [3]
Question 5
For each example 1 mark for correct structure, 1 mark for appropriate content inside loop and 1 mark for reason. There are many correct answers these are only samples REPEAT ..INPUT Number Total ← Total + Number UNTIL Number = 0 – at least one repeat is required WHILE Number <> -1 DO ..INPUT Number Total ← Total + Number ENDWHILE – the loop may never be executed [6]
Question 6
6(a)[2]
– Town has duplicate entries/all fields can have duplicate entries – fields other than Town not suitable identifiers [2]
6(b)[2]
– Performance number … – … uniquely identifies each performance [2]
6(c)[4]
Field: Town Tour Date Price Local Currency Table: THEATRETOURS THEATRETOURS THEATRETOURS Sort: Ascending Show: ;
;
;
Criteria: or: 1 mark for each column + 1 mark for correct fields only [4]