Problem 8 · 2017 Math Kangaroo
Medium
Counting & Probability
careful-countingratio
In which picture are there half as many circles as triangles and twice as many squares as triangles? (The five pictures are shown as choices A, B, C, D, E.)
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Answer: E
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Hint 1 of 2
For each picture, count the circles, the triangles, and the squares.
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Hint 2 of 2
You want the triangles to be in the middle: half as many circles, and double as many squares.
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Approach: count the shapes in each picture
- Count the three kinds of shape in each picture.
- We need a picture where the circles are the small group, the triangles are double the circles, and the squares are double the triangles.
- For example 1 circle, 2 triangles, 4 squares fits: circles are half the triangles and squares are twice the triangles.
- The picture that matches both rules is E.
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