# counting

• Oct 26th 2006, 04:52 AM
counting
Hi,
I would like to have some help with this problem about counting:

How many different three-letter initials with none of the letter repeated can people have?

I would say for the solution 23^3 since we have to remove 3 letter from the alphabet.
I am right?
Thank you
B
• Oct 26th 2006, 04:57 AM
earboth
Quote:

Hi,
I would like to have some help with this problem about counting:
How many different three-letter initials with none of the letter repeated can people have?...

Hi,

there 26 letters in the alphabet.

For the first initial you can choose one from the 26 letters.
For the second initial there are 25 left (one letter is used already)
For the third initial you have only 24 letters.

So the total amount of different 3-initials is: 26 * 25 * 24

EB
• Oct 26th 2006, 05:04 AM
Quote:

Originally Posted by earboth
Hi,

there 26 letters in the alphabet.

For the first initial you can choose one from the 26 letters.
For the second initial there are 25 left (one letter is used already)
For the third initial you have only 24 letters.

So the total amount of different 3-initials is: 26 * 25 * 24

EB

Thank you