# Thread: As easy as ABC

1. ## As easy as ABC

ABC is a number, where A, B and C are different integers.

Find ABC, where:

ACB+BCA+BAC+CBA+CAB=4539

2. ## Re: As easy as ABC

<span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">ABC = 789</span hide>

3. ## Re: As easy as ABC

Well done Hans [choccy bar]

Just as a matter of interest, was this done with Excel, or did you do it by mathematical proof?

4. ## Re: As easy as ABC

<span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">I wrote an equation for A, B and C:

122A + 212B + 221C = 4539

It's clear that C must be odd to get an odd sum. An order of magnitude estimation shows that B and C must be in the 8 to 9 range to get the sum over 4000, so B = 8 and C = 9. A folllows.</span hide>

5. ## Re: As easy as ABC

Cool

That is what I had, just checking <img src=/S/evilgrin.gif border=0 alt=evilgrin width=15 height=15>

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