Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2012-01-10 22:25:40

anna_gg
Member
Registered: 2012-01-10
Posts: 113

Make 1000 using 6 8's

Use number 8 6 times to make 1000.
You can only use +, -, *, /, square root and parenthesis ().
No factorials, 3rd root or any other numbers.

Thank you!!!
wave

Offline

#2 2012-01-11 00:52:13

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,676

Re: Make 1000 using 6 8's

Hi anna_gg;

Welcome to the forum! Do you know whether this has an answer or not?


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Offline

#3 2012-01-11 01:29:29

anna_gg
Member
Registered: 2012-01-10
Posts: 113

Re: Make 1000 using 6 8's

It does, but I don't know it! All my attempts end up in using 7 8's or more!

Offline

#4 2012-01-11 01:39:19

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,676

Re: Make 1000 using 6 8's

Yes, there are lots of solutions for 8 8's and perhaps for 7 8's also. But I have never seen one for 6 8's.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Offline

#5 2012-01-11 03:09:56

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,393

Re: Make 1000 using 6 8's

hi anna_gg and bobbym

I've got some 7 eights solutions.  But 6 is still eluding me.  sad

Bob

The five weighings problem is getting very complicated.

I'm doing things like balance 2 unknowns against 1.

If they balance then they must be (10,20,30) or (10,30,40) or (10, 40,50) or (20,30,50)

If the two go down then (10,20,40) or (10,20,50) or (10,30,50)

If not then there's loads of possibilities eeekkk.

Depending on which, try other balance possibilities.

The total map of alternatives is very large!

OR

(Im)Balance any pair and call them v and w so that v<w

(Im)Balance another pair and call them x and y so that x < y.

Then try w against x.  Again lots of possibilities.

Cannot find a simple, elegant way to tackle this.

Last edited by bob bundy (2012-01-11 03:12:06)


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

Offline

#6 2012-01-11 07:08:44

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,393

Re: Make 1000 using 6 8's

hi anna_gg

Bob

Last edited by bob bundy (2012-01-11 07:11:21)


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

Offline

#7 2012-01-11 09:48:40

anna_gg
Member
Registered: 2012-01-10
Posts: 113

Re: Make 1000 using 6 8's

We are only allowed to use decimals in the form 8.8, not .8, as this assumes leading zeros sad
Otherwise, another like that would be 888/.888.

Offline

#8 2012-01-12 02:12:48

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,393

Re: Make 1000 using 6 8's

hi anna_gg

Please would you post the exact wording in the original question. 

I'm 'clutching at straws' now.

Bob


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

Offline

#9 2012-01-12 02:18:38

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,676

Re: Make 1000 using 6 8's

Hi;

I have done a large computer search for some answer, also a search of the available literature for these type problems. I am coming up dry.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Offline

#10 2012-01-12 02:22:05

benice
Member
Registered: 2010-06-10
Posts: 110

Re: Make 1000 using 6 8's

1000 = 10^3

10 = 8 + sqrt( sqrt(8+8) )
3 = sqrt(8 + 8/8)

Last edited by benice (2012-01-12 02:22:58)


My Gallery of Math Art: benice equation

Offline

#11 2012-01-12 02:28:18

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,676

Re: Make 1000 using 6 8's

Hi;

Are exponents allowed? I thought they were not.

Hi Benice;

If they are then nice solution!


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Offline

#12 2012-01-12 02:46:00

anna_gg
Member
Registered: 2012-01-10
Posts: 113

Re: Make 1000 using 6 8's

Awesome! Thanks!!!wave

Offline

#13 2012-01-12 02:53:06

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,393

Re: Make 1000 using 6 8's

It is a nice solution.

But I thought you weren't allowing powers.

That's why I asked for the exact wording.

So is this question done now?

Bob


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

Offline

#14 2012-01-12 02:57:03

anna_gg
Member
Registered: 2012-01-10
Posts: 113

Re: Make 1000 using 6 8's

Not sure about powers; I must confirm this with the friend who gave me the problem.
Either way, I could not go that close myself!

Offline

#15 2012-01-12 03:02:11

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,676

Re: Make 1000 using 6 8's

Hi anna_gg;

If it does not include powers can you have your friend clearly state what is good and what is not?


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Offline

#16 2012-01-12 08:20:55

anna_gg
Member
Registered: 2012-01-10
Posts: 113

Re: Make 1000 using 6 8's

Confirmed that powers are allowed!

Offline

#17 2012-01-12 11:25:23

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,676

Re: Make 1000 using 6 8's

Hi;

Then I guess this question is closed unless you want more of them.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Offline

#18 2012-01-13 08:30:09

anna_gg
Member
Registered: 2012-01-10
Posts: 113

Re: Make 1000 using 6 8's

Thank you all for your help!!

Offline

Board footer

Powered by FluxBB