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2021 Math Kangaroo

Problem 3

Problem 3 · 2021 Math Kangaroo Easy
Arithmetic & Operations order-of-operations

What is the value of \(\dfrac{20\cdot 21}{2+0+2+1}\)?

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Answer: D — 84
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Hint 1 of 2
Work out the bottom of the fraction first — it is just an addition.
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Hint 2 of 2
Then a single division finishes it.
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Approach: evaluate denominator, then divide
  1. The denominator is 2+0+2+1 = 5.
  2. The numerator is 20·21 = 420.
  3. 420 ÷ 5 = 84.
  4. So the answer is D.
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