# Thread: A 10-digit number puzzle

1. ## A 10-digit number puzzle

Note: This is not an original puzzle, I borrowed it from a University website...

Find a ten-digit number whose first digit is the number of ones in the ten-digit number, whose second digit is the number of twos in the ten-digit number, whose third digit is the number of threes in the ten-digit number, whose fourth digit is the number of fours in the ten-digit number, continuing to the tenth digit which will be the number of zeros in the ten-digit number.

<img src=/S/cheers.gif border=0 alt=cheers width=30 height=16>

2. ## Re: A 10-digit number puzzle

<span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">1000000008</span hide>

3. ## Re: A 10-digit number puzzle

<img src=/S/bravo.gif border=0 alt=bravo width=16 height=30> - This is a great way to keep your kids busy for awhile. Almost like the piece of paper that says "please turn over" on both sides... <img src=/S/smile.gif border=0 alt=smile width=15 height=15>

4. ## Re: A 10-digit number puzzle

But the 8th digit in Jezza's solution is 0, so there shouldn't be any 8s in the number... <img src=/S/scratch.gif border=0 alt=scratch width=25 height=29>

5. ## Re: A 10-digit number puzzle

You are right Hans, I popped out to the shop and during the journey realised i was wrong, so I am not accepting a prize for this one...I think Tricky needs to keep it open.

6. ## Re: A 10-digit number puzzle

You know what? You're right. I came up with the same solution to the puzzle that Jezza did and I automatically assumed it was correct. No wonder it seemed too simple. My answer was incorrect, as well. So, at this point, I do not know the solution... Back to the drawing board.

<img src=/S/brickwall.gif border=0 alt=brickwall width=25 height=15>

7. ## Re: A 10-digit number puzzle

How about <span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold"><code>2100010006</code></span hide>

8. ## Re: A 10-digit number puzzle

Yep

The White House Kids Website says you are, who would want to argue <img src=/S/duck.gif border=0 alt=duck width=23 height=23> <img src=/S/grin.gif border=0 alt=grin width=15 height=15>

9. ## Re: A 10-digit number puzzle

<img src=/S/laugh.gif border=0 alt=laugh width=15 height=15> I had just figured it out and was rushing back to the board to post a solution to my own puzzle and found that you beat me to it. Too funny. I originally brushed this one off as too simple to solve and it ended up being a nice challenge.

10. ## Re: A 10-digit number puzzle

Yep, it's a nice puzzle. <img src=/S/thumbup.gif border=0 alt=thumbup width=15 height=15>

Brute force probably wouldn't work here, so you have to reason it out.

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