Decode the pattern — 4 − 4 = 12, 6 − 6 = 30, 2 − 2 = 2. Compute 8 − 8.
Verbal Reasoning
Mathematical Operations
Difficulty: Easy
Choose an option
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A8
-
B38
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C56
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D16
Answer
Correct Answer: 56
Explanation
Introduction / Context:These are not real subtractions; the symbol “−” encodes a number-to-number mapping. We must infer a single rule consistent with all given examples and apply it to 8 − 8.
Given Data / Assumptions:
- 4 − 4 = 12
- 6 − 6 = 30
- 2 − 2 = 2
Concept / Approach:Try simple expressions in n such as n^2 ± n or linear forms. Observing: 4 → 12 suggests 4^2 − 4 = 12; 6 → 30 suggests 6^2 − 6 = 30; 2 → 2 suggests 2^2 − 2 = 2. Hence the rule fits all: f(n) = n^2 − n.
Step-by-Step Solution:
Identify rule: f(n) = n^2 − n.Compute for n = 8: f(8) = 8^2 − 8 = 64 − 8 = 56.Verification / Alternative check:Check the rule on all given examples to confirm consistency (it matches all three).
Why Other Options Are Wrong:
- 8, 16, 38 do not follow the deduced quadratic rule.
Common Pitfalls:
- Assuming real subtraction instead of a coded pattern.
Final Answer:56