18. Solve the following problem, asked of Marilyn Vos Savant in the “Ask Marilyn” column of Parade Magazine, August 9, 1992.

Three of us couples are going to Lava Hot Springs next weekend. We’re staying two nights, and we’ve rented two studios, because each holds a maximum of only four people. One couple will get their own studio on Friday, a different couple on Saturday, and one couple will be out of luck. We’ll draw straws to see which are the two lucky couples. I told my wife we should just draw once, and the loser would be the couple out of luck both nights. I figure we’ll have a two-out-of-three (662 3%) chance of winning one of the nights to ourselves. But she contends that we should draw straws twice—first on Friday and then, for the remaining two couples only, on Saturday—reasoning that a one-in-three (331 3%) chance for Friday and a one-in-two (50%) chance for Saturday will give us better odds. Which way should we go?