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

Respuesta :

Permutation.
you have 26 options for the slot 1, 9 options for slot 2, and 10 options for the last 6 slots. 
Therefore you just multiply each slot together
26•9•10•10•10•10•10•10
=234000000