Canoness Cucumbers

Three nuns went to a vegetable stand in an open market one day. They asked how much the cucumbers were.
The merchant said that they were 25 cents a piece.
The nuns huddled into a discussion and decided to purchase four.
The puzzled merchant asked why they needed four cucumbers when there were only three of them.
A nun answered back, “Well, I suppose we could always eat the extra one.”