Let be as in problem 14. Find the maximum such that three circles of radius can simultaneously fit inside an equilateral triangle of area without overlapping each other.
Solution
We first find that, in problem 15, each of the circles of radius is the incircle of a triangle formed by cutting the equilateral one in half. The equilateral triangle itself has sidelength , so the said inradius is so that Now we guess that and see that, miraculously, everything works: in the problem 14, say a crimson flower is placed first. Then there are 2 possibilities for for for , and 2 for , giving a total of 10. Of course, the first flower can be of any of the three hues, so . We compute and check in a straightforward manner. If , then , and , with the result that , a contradiction. Assuming results in a similar contradiction.
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