Problem 6 · 1992 AJHSME
Medium
Algebra & Patterns
custom-operation
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Answer: D — 1.
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Hint 1 of 3
A new symbol is just a recipe. The worked example tells you the recipe is "top + bottom-left − bottom-right." Read the example to decode the rule before touching the question.
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Hint 2 of 3
"Made-up operation" problems are about following the given pattern exactly — match each number to its slot, don't invent your own order.
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Hint 3 of 3
Compute each triangle to a single number first, THEN combine; don't mix the two triangles' numbers together.
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Approach: decode the rule from the example, then apply it slot-by-slot
- The example 5 + 4 − 6 = 3 tells us the rule: top + bottom-left − bottom-right.
- First triangle (top 1, left 3, right 4): 1 + 3 − 4 = 0. Second triangle (top 2, left 5, right 6): 2 + 5 − 6 = 1.
- Now add the two results: 0 + 1 = 1.
- Why this transfers: any "define a strange symbol" problem is really a substitution exercise — the only skill is plugging each value into the right position of the given formula. No cleverness needed, just careful matching.
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