The owner of a motel with 100 rooms wants the room doors numbered in order from 1 to 100. She asks you to buy numbers and hang them on the doors. Now you must go to the store and buy all the digits you need to make the numbers.
How many of each digit, 0 to 9, must you buy?
Answer
You will need twenty-one 1s, twenty each of 2 through 9, and eleven 0s.
