A warranty identification number for a certain product consists of a letter of the alphabet followed by a four-digit number. How many possible identification numbers are there if the first digit of the four-digit number must be nonzero?

Question

anonymous · Answer

We have five slots to fill.
The first on must be a letter from the alphabet
The second must be 0 to 9
The thrid must be 0 to 9
The fourth must be 0 to 9
The fifth must be 1 to 9

anonymous · Answer

Find many possibilities for each slots and multiply them to get the answer.