What kind of room has no doors...

A 6th-grade teacher posed the following problem to one of her arithmetic classes:
“A wealthy man dies and leaves ten million dollars.
One-fifth is to go to his wife, one-fifth is to go to his son, one-sixth to his butler, and the rest to charity.
Now, what does each get?”
After a very long silence in the classroom, one little boy raised his hand.
With complete sincerity in his voice, answered, “A lawyer!”