To decide what to eat at a restaurant, Frank closes his eyes, places his finger on the menu, and orders whichever dish he places his finger on. He chooses one salad, one main course, and a dessert. If there were 10 possible dishes for each selection, how many possible combinations could he have chosen other than the one he selected?
There are 10 possible salads, 10 possible main courses,
and 10 possible desserts.
If a meal consists of 1 salad, 1 main course, and 1 dessert, then
he could have picked (10 x 10 x 10) = 1,000 different meals.
There are 999 other possibilities besides the one he picked.