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2016 Math Kangaroo

Problem 4

Problem 4 · 2016 Math Kangaroo Easy
Algebra & Patterns work-backward

Jim should have added 26 to a certain number. Instead he subtracted 26 and obtained −14. What result would he have obtained if he had added 26?

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Answer: D — 38
Show hints
Hint 1 of 2
First recover the original number from what actually happened.
Still stuck? Show hint 2 →
Hint 2 of 2
He subtracted 26 to get −14, so add 26 back, then add 26 once more for the intended operation.
Show solution
Approach: undo to find the number, then redo correctly
  1. He subtracted 26 and got −14, so the number is −14 + 26 = 12.
  2. Adding 26 to it (what he should have done) gives 12 + 26 = 38.
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