Boolean logic can be applied to real-world scenarios by converting conditions into logic gates and truth tables. For example, a security system might grant access only when a keycard AND a PIN are provided. You need to be able to design truth tables and logic circuits for given scenarios, and determine outputs for specific input combinations.
Key points
Real-world problems can be modelled using Boolean logic and truth tables.
Identify the inputs (conditions) and the desired output for the scenario.
Watch for NOT conditions in the scenario: 'nighttime' when the sensor input is 'daytime' means NOT B.
Choose appropriate gates (AND, OR, NOT) to produce the correct output.
Build the truth table showing all possible input combinations and the resulting output.
Draw the corresponding logic circuit diagram using standard gate symbols.
Exam Example:Floodlight on when switch ON (C) AND motion detected (A) AND nighttime (NOT B, since B=daytime). Q = A AND NOT B AND C — needs NOT gate on B and two AND gates.
Exam Example:Cinema: customer 15+ (A) AND (has ticket (B) OR has money (C)). P = A AND (B OR C).
Exam Example:Restaurant: half-price if (student (A) OR discount card (B)) AND NOT Saturday (C). P = (A OR B) AND NOT C.
Exam Tip:Read the scenario carefully for hidden NOT conditions. 'Not valid on Saturdays' means NOT C. 'At nighttime' when sensor measures daylight means NOT B.