Problem 14 · 2012 Math Kangaroo
Medium
Arithmetic & Operations
total-then-divide
15 tables were set for a party. 5 plates were laid on 6 of the tables. 3 plates were laid on the rest of the tables. How many plates were needed in total?
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Answer: C — 57
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Hint 1 of 2
Find how many tables get 3 plates after 6 tables get 5 plates.
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Hint 2 of 2
Work out each group's plates and add them.
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Approach: split into two groups of tables
- 6 tables get 5 plates each: 6 x 5 = 30 plates.
- The other 15 - 6 = 9 tables get 3 plates each: 9 x 3 = 27 plates.
- Altogether 30 + 27 = 57 plates are needed.
- The answer is 57.
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