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MathNet 2009-part-05 — 172 problems (EN–VI) Question 106

Math Olympiad Vault · MathNet 2009-part-05 — 172 problems (EN–VI)

Question 106

There are 5 students on a team for a math competition. The math competition has 5 subject tests. Each student on the team must choose 2 distinct tests, and each test must be taken by exactly two people. In how many ways can this be done?