Which rules would make this input-output pair true?

input
6
rule
Input Output Arrow
?
Input Output Arrow
output
12
Could be a rule for this input-output pair Could not be a rule for this input-output pair
Multiply by 2, then add 3.
Multiply by 2.
If even, write 19. If odd, subtract 3.
Write 12.
Add 11.
Subtract 3, then multiply by 4.

1 answer

To determine which rules would make the input-output pair of 6 producing an output of 12 true, we can evaluate each of the proposed rules:

  1. Multiply by 2, then add 3.

    • Calculation: \(6 \times 2 + 3 = 12 + 3 = 15\)
    • Output: 15 (Not equal to 12)
    • Could not be a rule for this input-output pair.
  2. Multiply by 2.

    • Calculation: \(6 \times 2 = 12\)
    • Output: 12 (Equal to 12)
    • Could be a rule for this input-output pair.
  3. If even, write 19. If odd, subtract 3.

    • Since 6 is even, according to the rule, the output would be 19.
    • Output: 19 (Not equal to 12)
    • Could not be a rule for this input-output pair.
  4. Write 12.

    • This rule directly specifies the output as 12 regardless of the input.
    • Output: 12 (Equal to 12)
    • Could be a rule for this input-output pair.
  5. Add 11.

    • Calculation: \(6 + 11 = 17\)
    • Output: 17 (Not equal to 12)
    • Could not be a rule for this input-output pair.
  6. Subtract 3, then multiply by 4.

    • Calculation: \((6 - 3) \times 4 = 3 \times 4 = 12\)
    • Output: 12 (Equal to 12)
    • Could be a rule for this input-output pair.

Summary:

  • Could be a rule for this input-output pair:

    • Multiply by 2.
    • Write 12.
    • Subtract 3, then multiply by 4.
  • Could not be a rule for this input-output pair:

    • Multiply by 2, then add 3.
    • If even, write 19. If odd, subtract 3.
    • Add 11.