Question

A three-character password consists of 2 different digits between 0 and 9, inclusive, and 1 letter of the English alphabet. The letter must appear as first or second character. How many different passwords are possible?
• A.
2340
• B.
94348800
• C.
188697600
• D.
4680

Answer 1

I would start with the number of options for each of the three characters
So, how many number options and how many letter options for the first character?

Answer 2

@kiran999

Answer 3

Well, let's say that the first character can be a number or a letter (one of the possibilities)--how many possibilities are there for that first slot?

Answer 4

Let's go back to the first step (on the board)
So there are two possibilities
Letter Number Number
Number Letter Number
So we need to calculate the number of options for each situation
And then add them together
So let's start with the first option
We would have a number for the first character
*letter
Sory!. So there are 26 letters in the alphabet to choose from.

Answer 5

back

Answer 6

The next number you need is how many numbers are possible...if you have 0 - 9, how many numbers is that? 10 right?