Putnam 2017 A6
- Session A
The 30 edges of a regular icosahedron are distinguished by labeling them . How many different ways are there to paint each edge red, white, or blue such that each of the 20 triangular faces of the icosahedron has two edges of the same color and a third edge of a different color? [Note: the top matter on each exam paper included the logo of the Mathematical Association of America, which is itself an icosahedron.]
Curated text Kedlaya Putnam archive. Quoted with source.
Solutions
Human solution Solution 1 by Kiran Kedlaya and Lenny Ng
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