# Counting Problem

• Oct 27th 2013, 11:37 AM
troe
Counting Problem
Hello everyone. Can someone please point me in the right direction on how to solve the following problem:

How many different 3 letter initials are there that have at least an A in it?

Thanks.
• Oct 27th 2013, 12:06 PM
Plato
Re: Counting Problem
Quote:

Originally Posted by troe
Hello everyone. Can someone please point me in the right direction on how to solve the following problem:
How many different 3 letter initials are there that have at least an A in it?

How many total 3 letter initials are there possible?

How man 3 letter initials contain no A are there possible?

Now subtract.
• Oct 27th 2013, 02:06 PM
troe
Re: Counting Problem
How do I find how many 3 letter initials that contains A? Would it be easier to find how many 3 letter initials that don't contain an A and subtract that number from the total possibilities?
• Oct 27th 2013, 02:09 PM
Plato
Re: Counting Problem
Quote:

Originally Posted by troe
Would it be easier to find how many 3 letter initials that don't contain an A and subtract that number from the total possibilities?

Did you read reply#2? That is exactly what it says.
• Oct 27th 2013, 02:23 PM
troe
Re: Counting Problem
Thanks.