Ask a Foolish Question

Season 3 · Episode 8 · First aired May 13, 2011

When Candace discovers that Phineas and Ferb have invented a computer that can answer anything, she asks it how she can finally bust her brothers once and for all. Meanwhile, Dr. Doofenshmirtz loses the key to his latest invention, the "All Purpose-inator," and Agent P must find it before he does.

Summary from TVmaze · CC BY-SA