Problem 8 · 2016 Math Kangaroo
Medium
Arithmetic & Operations
work-backwarddivision
Grandma stands in the courtyard calling her cat and all her chickens. After a little while, 20 legs come running towards her. How many chickens does Grandma have?
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Answer: C — 8
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Hint 1 of 2
The cat has 4 legs; every chicken has 2.
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Hint 2 of 2
Take away the cat's legs first, then split the rest into pairs.
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Approach: remove the cat's legs, then divide by two
- The cat accounts for 4 of the 20 legs, leaving 20 − 4 = 16 chicken legs.
- Each chicken has 2 legs, so there are 16 ÷ 2 = 8 chickens.
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