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A-LevelComputer ScienceProgrammingOct/Nov 2021Paper 4 Q117 Marks

Study the following pseudocode for a recursive function. FUNCTION Unknown(BYVAL X, BYVAL Y : INTEGER) RETURNS INTEGER IF X < Y THEN OUTPUT X + Y RETURN (Unknown (X + 1, Y) * 2) ELSE IF X = Y THEN RETURN 1 ELSE OUTPUT X + Y RETURN (Unknown (X 1, Y) DIV 2) ENDIF ENDIF ENDFUNCTION The operator DIV returns the integer value after division e.g. 13 DIV 2 would give 6

Q: What topic does this question test?

This question tests Programming in A-Level Computer Science (syllabus code 9618). It is worth 17 marks.

Q: Which exam paper is this question from?

This question appeared in the Cambridge A-Level Computer Science Oct/Nov 2021 examination, Paper 4 Variant 1 (9618_w21_qp_41.pdf).

📋 Examiner Report & Trap Analysis

Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...

🎯 Mark Scheme Breakdown

Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.

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About This A-Level Computer Science Question

Topic

This structured question tests Programming in A-Level Computer Science (syllabus code 9618). It is worth 17 marks.

Source

This question appeared in the Cambridge A-Level Computer Science Oct/Nov 2021 examination, Paper 4 Variant 1.

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