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2012 Math Kangaroo

Problem 7

Problem 7 · 2012 Math Kangaroo Easy
Arithmetic & Operations order-of-operations

The number 3 should be added to the number 6. This amount is then doubled, and the result is increased by 1. Which of the following sums fits this description?

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Answer: D — \((6 + 3) \times 2 + 1\)
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Hint 1 of 2
Translate the words step by step into an expression.
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Hint 2 of 2
'This amount is then doubled' means multiply the whole sum (6+3) by 2 first.
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Approach: translate words to an expression
  1. 'Add 3 to 6' gives (6 + 3).
  2. 'This amount is doubled' gives (6 + 3) x 2.
  3. 'the result increased by 1' gives (6 + 3) x 2 + 1, which is choice D.
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