3 Consider the logic statement: X = ((((NOT A AND B) OR C) AND B) NOR (B OR C)) (a) Draw a logic circuit to represent the given logic statement. Do not attempt to simplify the statement. All logic gates must have a maximum of two inputs. X B A C [6] (b) Consider the completed truth table for the given logic statement. Row number A B C Working space X 1 0 0 0 1 2 0 0 1 1 3 0 1 0 1 4 0 1 1 0 5 1 0 0 1 6 1 0 1 0 7 1 1 0 1 8 1 1 1 1 There are four errors in the truth table in the output (X) column. Identify the four incorrect outputs. Write the row number to identify each incorrect output. Row … Row … Row … Row … [4]

3(a) One mark for each correct logic gate with correct input. 6 3(b) One mark per each correct row. − Row 2 − Row 3 − Row 7 − Row 8 4

6 Consider the logic statement: X = (((A AND B) OR (C AND NOT B)) XOR NOT C) (a) Draw a logic circuit to represent the given logic statement. Do not attempt to simplify the statement. All logic gates must have a maximum of two inputs. X B A C [6] (b) Consider the completed truth table for the given logic statement. Row number A B C Working space X 1 0 0 0 0 2 0 0 1 1 3 0 1 0 0 4 0 1 1 1 5 1 0 0 0 6 1 0 1 1 7 1 1 0 0 8 1 1 1 1 There are four errors in the truth table in the output (X) column. Identify the four incorrect outputs. Write the row number to identify each incorrect output. Row … Row … Row … Row … [4]

6(a) One mark per each correct logic gate, with correct input: 6 6(b) − Row 1 − Row 3 − Row 4 − Row 5 4

11 Consider the following logic statement: X = (((A AND B) OR (NOT (B OR C))) NAND C) (a) Draw a logic circuit to represent the given logic statement. Do not attempt to simplify the logic statement. All logic gates must have a maximum of two inputs. A B X C [5] (b) Complete the truth table for the given logic statement. A B C Working space X 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 [4] (c) Identify two logic gates that are not included in the given logic statement. Logic gate 1 … Logic gate 2 … [2]

11(a) One mark per each correct logic gate with correct input(s) A B C X 5 11(b) 4 marks for 8 correct outputs 3 marks for 6/7 correct outputs 2 marks for 4/5 correct outputs 1 mark for 2/3 correct outputs A B C Working space X 0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 0 4 11(c) − NOR − XOR / EOR 2

2 Consider the logic statement: X = (((A NAND B) OR (B XOR C)) AND NOT C) (a) Draw a logic circuit to match the given logic statement. All logic gates must have a maximum of two inputs. Do not attempt to simplify the logic statement. X [5] (b) Complete the truth table to represent the given logic statement. A B C Working space X 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 [4]

2(a) A B C X 1 mark for each correct gate. 5 2(b) A B C Working space X 0 0 0 1 0 0 1 0 0 1 0 1 0 1 1 0 1 0 0 1 1 0 1 0 1 1 0 1 1 1 1 0 4 marks for 8 correct outputs 3 marks for 6 or 7 correct outputs 2 marks for 4 or 5 correct outputs 1 mark for 2 or 3 correct outputs 4

4 (a) Identify the name and draw the single logic gate that can replace the given logic circuits. (i) A B X Name of gate: …………………………… Drawing of gate: [2] (ii) A B X Name of gate: …………………………… Drawing of gate: [2] (b) Complete the truth table for the given logic statement: X = (((A OR C) AND (NOT A AND NOT C)) XOR B) A B C Working space X 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 [4]

4(a)(i) − NAND 2 4(a)(ii) − NOR 2 4(b) A B C Working space X 0 0 0 0 0 0 1 0 0 1 0 1 0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 1 1 1 1 1 4 marks for 8 correct outputs 3 marks for 6 or 7 correct outputs 2 marks for 4 or 5 correct outputs 1 mark for 2 or 3 correct outputs 4

Cambridge O Level Computer Science · 2210

O-Level Computer Science (2210) Boolean logic past paper questions

Revise O-Level Computer Science (2210) — Boolean logic with real Cambridge past-paper questions grouped by topic, each shown with its marking scheme. Working one topic at a time targets exactly the skill each question tests.

23 free questions from 2016–2021, each with its marking scheme. Open the full topical bank to filter by subtopic, paper, and year.