Problem 3 · 2019 Math Kangaroo
Easy
Logic & Word Problems
careful-counting
In a nursery group there are 14 girls and 12 boys. Half of the group go for a walk. What is the minimum number of girls that have to be amongst that group?
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Answer: E — 1
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Hint 1 of 3
First find how many children go for the walk: it is half of the whole group.
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Hint 2 of 3
To make girls as few as possible, imagine sending all the boys first.
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Hint 3 of 3
Once the boys are used up, see how many walking spots are still empty.
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Approach: fill the walking group with boys first
- There are 14 + 12 = 26 children, so half of them, 13, go for the walk.
- We want as few girls as possible, so picture sending boys first: there are only 12 boys, and they fill 12 of the 13 spots.
- That leaves 13 − 12 = 1 spot, which must go to a girl, so the smallest number of girls is 1 (E).
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