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2024 Math Kangaroo

Problem 13

Problem 13 · 2024 Math Kangaroo Hard
Ratios, Rates & Proportions proportion

Uli can buy exactly 12 packages of jelly babies or exactly 20 chocolate bars with her pocket money. Uli buys 9 packages of jelly babies. How many chocolate bars can she buy with the remaining money?

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Answer: C — 5
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Hint 1 of 2
Think of her whole pocket money as one amount split into 12 jelly-baby shares or 20 chocolate shares.
Still stuck? Show hint 2 →
Hint 2 of 2
Buying 9 of the 12 jelly packages uses 9/12 = 3/4 of the money, so a quarter is left.
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Approach: convert the leftover fraction of money into chocolate bars
  1. Her money buys 12 jelly packages, so 9 packages cost 9/12 = 3/4 of it.
  2. That leaves 1/4 of her money.
  3. Her money buys 20 chocolate bars, so 1/4 buys 20 × 1/4 = 5 bars.
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