## Tuesday, November 15, 2005

### Math is Fun!

Alright kids, get out your pencils and make a cup of coffee, because this one will keep you up at night.

Using the digits 1 through 9, with no repeats, find two numbers, where the larger one is exactly double the smaller one.

Thank my Dad for this one - he gave it to me last night, and I got the right answer at quarter to midnight. I know there is one solution, but is it unique? There may be more than one correct answer!

The first commenter with the correct answer will recieve the grand prize, which is the satisfaction of being the first one right, along with the dubious honor of being called a Math Geek like me. (And for those of you who don't want to play, I'll post my answer in the comments section later.) Ready? Set? GO!

Sheila said...

My dad just told me there is more than one right answer. Aw cripes, where's that pencil?

Sherry C said...

8 and 4, 6 and 3, 70 and 35, 64 and 32...

There must be something I am missing here.

Sherry C said...

Oh, perhaps I'm supposed to use ALL the digits?

Sheila said...

Yes, Sherry, ALL the digits. Here's a hint: one of them is a four digit number, the other a five digit number. No zeros, no repeats.

Sherry C said...

I have an answer, using all the digits 1-9, no repeats. Elapsed time: 12 minutes. And I didn't just totally get lucky either--I actually was working a little system.
And then I suppose I did get lucky with choosing the right combination within my system.

I'll post my answer in the comments section of my most recent post on my blog.

Do I win? Do I win? Do I get to be an honorary math nerd?

Sherry C said...

Ok, let the record show that your hint, which appears here before my triumphant response, WAS NOT THERE when I posted my answer. We must have been commenting simultaneously or something. I did it without your hint. So there.

Sherry C said...

Ok, I suppose my concern over seeing or not seeing your hint is silly. If there are nine digits to work with, then of course it has to be a four digit number and a five digit number.

jaymarie said...

i can't even tell you how i am not getting what you are talking about, i do not comprehend this in the least...

ask Kyle - he will probably get it pretty quickly.

Stephanie said...

i'm lost too. I thought each number, huh?...oh never mind. I'm good at math but apparently not at following directions. Oh well. I'll try again another day.

Sheila said...

Here it is. A lengthy comment with the solutions. First, let me tell you how I did it. The smaller number must have four digits, and must be between 6200 and 9800. (Actually, between 6345 and 9467, since doubling numbers outside this range gives duplicate digits) Then I made a list and looked for correct answers. I found ten.

The solutions are:
6927 (13854)
7269 (14538)
7293 (14586)
7329 (14658)
7692 (15384)
7923 (15846)
7932 (15864)
9267 (18534)
9273 (18546)
9327 (18654)

K Murphy J said...

:) I am so glad I came into this conversation AFTER you posted the answers. Now, I have a ready made excuse for why I would never have gotten any of these answers. :)

AmberJ said...

I wouldn't have got this with or without the answers...yes I'm one of those kids that looks -- I mean looked -- up the answer in the back of the book before reading the whole problem.

(sigh)

I was thinking along the lines of single digit numbers...8, 6,...that's as far as I got.

Bravo and Standing "O" to Sheila and sherry c for figuring this out.

As I said before. Give me a sentence to diagram any day.