Standard +0.3 This is a standard proof by contradiction following the classic template for proving √n is irrational (assume √6 = p/q in lowest terms, square both sides, show p² is divisible by 6 hence p is divisible by 6, substitute to show q² is also divisible by 6, contradiction). While it requires understanding proof structure, it's a direct application of a well-rehearsed technique with no novel insight needed, making it slightly easier than average.