Computers carry out comparisons - Edexcel - GCSE Computer Science - Question 2 - 2021 - Paper 1

To fill in the truth table, we need to evaluate the logical expressions for each row using the standard logical operations:

1. For Y AND Z: This expression is true (1) if both Y and Z are true (1). Therefore, it will be 1 only when both Y and Z in a row are 1, and 0 otherwise:

   • Row 1: Y = 1, Z = 0 → 0
   • Row 2: Y = 1, Z = 1 → 1
   • Row 3: Y = 0, Z = 0 → 0
   • Row 4: Y = 0, Z = 1 → 0
   • Row 5: Y = 1, Z = 0 → 0
   • Row 6: Y = 1, Z = 1 → 1
   • Row 7: Y = 1, Z = 0 → 0
   • Row 8: Y = 0, Z = 1 → 0
   • Row 9: Y = 0, Z = 0 → 0

2. For X OR (Y AND Z): This expression is true (1) if either X is true or both Y and Z are true. We evaluate it accordingly:

   • Row 1: X = 0, Y AND Z = 0 → 0
   • Row 2: X = 0, Y AND Z = 1 → 1
   • Row 3: X = 1, Y AND Z = 0 → 1
   • Row 4: X = 1, Y AND Z = 0 → 1
   • Row 5: X = 1, Y AND Z = 0 → 1
   • Row 6: X = 1, Y AND Z = 1 → 1
   • Row 7: X = 0, Y AND Z = 0 → 0
   • Row 8: X = 1, Y AND Z = 0 → 1
   • Row 9: X = 1, Y AND Z = 0 → 1

Thus, the complete truth table will be:

X	Y	Z	Y AND Z	X OR (Y AND Z)
0	0	0	0	0
0	0	1	0	0
0	1	0	0	0
0	1	1	1	1
1	0	0	0	1
1	0	1	0	1
1	1	0	0	1
1	1	1	1	1