Math Is Fun Forum

goggles1980

Member

Registered: 2006-01-12

Posts: 1

Puzzle

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

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Puzzle

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.

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MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: Puzzle

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!

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

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: Puzzle

Heres one:  what comes next in this sequence:

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

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

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"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..."

justlookingforthemoment

Moderator

Registered: 2005-05-26

Posts: 2,161

Re: Puzzle

8
u u u u   
u u u

Maybe something to do with 'you underrate'?

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,418

Re: Puzzle

Sensible thinking. But why 7 'u's?

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Zach

Member

Registered: 2005-03-23

Posts: 2,075

Re: Puzzle

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

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mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Puzzle

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.

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Why did the vector cross the road?
It wanted to be normal.

mathaholic

Member

From: Earth

Registered: 2012-11-29

Posts: 3,251

Re: Puzzle

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

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

mathaholic

Member

From: Earth

Registered: 2012-11-29

Posts: 3,251

Re: Puzzle

Or it is 83 'cause it is prime.

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

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Puzzle

Well, 73 is also prime...

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