Fundamental Principle of Counting Problem

AI Thread Summary
A license plate consists of three letters followed by three digits, with the digits ranging from 0 to 9 but excluding the combination of all three being zero. The problem revolves around calculating the total number of possible combinations while adhering to this restriction. The initial calculation of 26^3 for letters and 10^3 for digits, minus the invalid combination of 000, leads to confusion about the correct setup. The correct approach involves recognizing that there are 999 valid combinations for the digits when excluding 000. Ultimately, the total number of possible license plates is derived from the product of valid letter and digit combinations.
LisaL
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Homework Statement



A license plate has three letters followed by three numbers. Suppose the digits from 0...9 can be used, except all three digits cannot be zero, and that any letter from A-Z with repeats can be used. How many plates are possible?

Homework Equations



My question is on the 0. Does this mean NONE can be used or only TWO?

The Attempt at a Solution

I was marked wrong for the following:

I set up as 26 x 26 x 26 x 10 x 10 x 9 = 15,818,400

What is the correct way to set up this problem?

Thanks!
 
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Ignore the letters for now. If you could have 3 digits with no restrictions, how many numbers can you form? Now if you exclude the possibility of all three being zeros, how many do you have left?
 
vela said:
Ignore the letters for now. If you could have 3 digits with no restrictions, how many numbers can you form? Now if you exclude the possibility of all three being zeros, how many do you have left?

OK, your point is made. The numbers 000 to 999 not including 000 total nine hundred and ninety nine. On the other hand 10x10x9 seems like it ought to work.
 
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