There are two soups, A and B, each starting with n ml. On every turn one of four servings is chosen, each with probability 1/4, as the amounts of (A, B): (100, 0), (75, 25), (50, 50), (25, 75). If a soup has less than the serving asks for, it serves what is left. The process stops when at least one soup is empty. Return P(A becomes empty first) + 0.5 * P(A and B become empty on the same turn). An answer within 1e-5 of the true value is accepted.
soupServings(50) is 0.625soupServings(100) is 0.71875n is up to 10^9, so a table over the volumes will not do