# Shout out to the first person to solve this puzzle.

I'll give a shout out to the first person who solves this puzzle with an explanation of how they did it. Once someone gets it I'll post round 2. *(Puzzles taken from Project Euler @ projecteuler.net)*.

### Chapter 1

## [Round 1]

**If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.**

Find the sum of all the multiples of 3 or 5 below 1000.

Find the sum of all the multiples of 3 or 5 below 1000.

Congrats to http://www.quibblo.com/user/Leopardsong (NineBeforeTen)!

Correct Answer:

**233168**

http://www.quibblo.com/user/flow_wolf/photoalbum/2393270 (The code I used.)

## 40 Comments

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"Although mathematics will help you arrive at elegant and efficient methods, the use of a computer and programming skills will be required to solve most problems."

Yeah, no thanks. I'm not too fond of puzzles like that. I think I'm going to have to drop out if you're going to continue with those, sorry to disappoint (lol we all know nobody is disappointed)

I'm going to lurk and watch the problems but I probably won't be posting my guesses.

A lot of people just use pen and paper or MS Excel to do them. You should still be able to do a lot of them if you want :)

I actually just looked through the first few problems and it looks like they're too complicated for just paper, and l already said I don't like using computers to solve things. I hardly even ever use calculators, actually.

I never liked math...XC

The last word was : 233168

Now I have it! I was wrong in saying there were 100 sets of each. There are 33 for 3 and 20 for 5. The sums of the sets are 5445 and 5500, adding up to 10,945.

Please?

It's 44,000, I think, as my next guess.

My first answer of 2,300 was wrong because I failed to account for the changing numbers with the larger set of multiples. 3, 6, 9 does NOT repeat. It repeats once you hit 30 with 3 and 50 with 5. The sums of the two sets are 165 and 275 respectively. Add those to get 440 and then multiply by 100 because of 100 sets of each.

I'm most likely wrong, the last step seems wonky, but I tried.

Nope, sorry buddy.

And it even took me more than three minutes. Boo. Back to the drawing board.

Ugh. Fine, I think I know how to solve it correctly. I need but three minutes.

2300?

It's in no language; just computer coding. Try using it as a code~

I mean what coding language is it in? Like, I used Python when I was working it out, what did you use?

Oh, Cprogramming

Really? Math? -_-

3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60, 63, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93, 96, 99, 102, 105, 108, 111, 114, 117, 120, 123, 126, 129, 132, 135, 138, 142, 145, 148, 151, 154, 157, 160, 163, 166, 169, 172, 175, 178, 181, 184, 187, 190, 193, 196, 199, 202, 205, 208, 211, 214, 217, 220, 223, 226, 229, 232, 235, 238, 241, 244, 247, 250, 253, 256, 259, 262, 265, 268, 271, 274, 277, 280, 283, 286, 289, 292, 295, 298, 301, 304, 307, 310 ..

OH MY GOD, DELETE THAT COMMENT, NVM

What the flip were you doing?

I read it wrong and thought you meant to show all the multiples of 3 and 5 below 1000, didn't see the

sumAH! MATHS! MATHS IS EVIL!

Haha, but

whydon't you like it?I just dont like it. I'm a writer, photographer, and animal behaviorist. I've never liked math.

Fair enough :) I'm more into computer science and software engineering so maths is just something I naturally like. Whatever floats your boat I suppose :)