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**goggles1980****Member**- Registered: 2006-01-12
- Posts: 1

Which number doesn't belong in this set?

73, 83, 86, 93

Obvious (ie. 86 because it's even) ? Or am I missing a deeper meaning of these numbers?

Another one, this one is for sure difficult.

What is depicted by the following:

8

u u u u

u u u

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**mathsyperson****Moderator**- Registered: 2005-06-22
- Posts: 4,900

That's the problem with puzzles like that. You give a perfectly sensible answer, and then the designer of the puzzle says that the actual answer is something different and complex and feels really proud of themselves, even though they're actually just being childish.

e.g. What comes next in this sequence? A, A, A, A, A...?

Any sane person would answer A, but nooooo... the idiot who calls themselves a puzzle-maker says 'no yore rong cos its acshully the first leter of the continants lol'

Anyway, your answer is fine. It's probably not the intended one, but it's certainly the simplest.

The second puzzle is harder. I can't think of anything right now, but I'll keep pondering for a while.

Why did the vector cross the road?

It wanted to be normal.

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,604

73 and 83 are primes, 86 and 93 are composite, so it isn't that.

And the other puzzle? Something to do with the eight being over 7 "u"s. They might look like "c" sideways? Seven Seas?

BTW: I like your continents one!

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

Heres one: what comes next in this sequence:

9, 10, 11, 12, 13, 14...

Once you've looked that, try to guess the pattern...

"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."

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**justlookingforthemoment****Moderator**- Registered: 2005-05-26
- Posts: 2,161

goggles1980 wrote:

8

u u u u

u u u

Maybe something to do with 'you underrate'?

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 20,152

Sensible thinking. But why 7 'u's?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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**Zach****Member**- Registered: 2005-03-23
- Posts: 2,075

In return to Rod's C theory; 8 Continents over Seven Seas.

Boy let me tell you what:

I bet you didn't know it, but I'm a fiddle player too.

And if you'd care to take a dare, I'll make a bet with you.

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**mathsyperson****Moderator**- Registered: 2005-06-22
- Posts: 4,900

But where do you get 'continents' from?

This is just an idea, but as they're c's on their side, it might be something do to with seaside.

Why did the vector cross the road?

It wanted to be normal.

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
- Posts: 3,246

I bet it's 86. Because the other 3 numbers end in 3.

Mathaholic | 10th most active poster | Maker of the 350,000th post | Person | rrr's classmate

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
- Posts: 3,246

Or it is 83 'cause it is prime.

Mathaholic | 10th most active poster | Maker of the 350,000th post | Person | rrr's classmate

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

Well, 73 is also prime...

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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