February 25, 2014

Problem of the Week

for Tuesday, February 25, 2014

Of the 400 Saint Ann's students that are permitted to go out for lunch, 90 percent go out and 10 percent stay in for lunch. When students are asked whether they go out for lunch, 90 percent tell the truth. Stanley says that he doesn't go out for lunch. What are the chances that he really doesn't go out for lunch?

Winners of the lunch problem