def solve(): """X = number of colors present X = X1 + X2 + ... + X7, where Xi = 1 if color i present else 0 EX = E(X1 + X2 + ... X6) EX = EX1 + EX2 + ... + EX6 EX = 7 * EX1 EX = 7 * (1 * p(color present)) EX = 7 * (1 - p(color absent)) EX = 7 * (1 - #(colors absent) / #(possibilities)) EX = 7 * (1 - 60 choose 20 / 70 choose 20) """ return round(7 * (1 - choose(60, 20) / choose(70, 20)), 10)
def solve(): ncr = (choose(n, r) for n in range(1, 101) for r in range(n)) return sum(1 for n in ncr if n > 1000000)