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Brain Teaser!
Posted: Wed Feb 15, 2006 2:09 pm
by Menlaan
Take the numbers '2' '4' '6' and '8'' and combine them using any arithmetic operations in any order (but using each number only once) to equal 25.
What's the solution?
I was asked this in an interview today and got stumped. Help NT!
Menlaan
Posted: Wed Feb 15, 2006 2:12 pm
by The Kizzy
I dont think its possible. All the numbers are even, and you are asked to come up with an odd solution.
Posted: Wed Feb 15, 2006 2:15 pm
by Menlaan
You can make odds by, for example taking 6 divided by 2. However, my interviewer indicated that that specific idea wasn't going to get me there. He also indicated that children have an easier time with this b/c you have to 'think outside the box."
Menlaan
Posted: Wed Feb 15, 2006 2:15 pm
by Harrison
Not enough restrictions, can you use the numbers more than once? Can you square/cube them? etc.
Posted: Wed Feb 15, 2006 2:17 pm
by Zanchief
Harrison wrote:Not enough restrictions, can you use the numbers more than once? Can you square/cube them? etc.
I was thinking of that before the children comment~
Posted: Wed Feb 15, 2006 2:18 pm
by Menlaan
You can use them only once, and you can use any arithmetic operations. The way I interpret that is that you can do 4^2 (or 4 squared), but that will use up '4' and '2'. You can also add, subtract, divide, etc.
Menlaan
Posted: Wed Feb 15, 2006 2:34 pm
by Eldred
2+8= 10
1+0= 1
4*6= 24
1+24= 25
Posted: Wed Feb 15, 2006 2:37 pm
by Zanchief
Eldred wrote:2+8= 10
1+0= 1
4*6= 24
1+24= 25
lame
Posted: Wed Feb 15, 2006 2:37 pm
by Harrison
1 isn't one of the numbers given, neither is 0.
Posted: Wed Feb 15, 2006 2:39 pm
by Harrison
And if you're able to use the subsequent numbers in the integers resulting from an operation, that wasn't stated either.
I.E.
(2+8=10) you didn't say we could take the resulting 1 and 0 that creates (10) and use them as such.
Posted: Wed Feb 15, 2006 2:39 pm
by Zanchief
10 = 1 and 0
Posted: Wed Feb 15, 2006 2:40 pm
by Harrison
See above
I don't know of any mathematical logic behind taking the 1 and 0 that makes (10) and use them seperately on their own.
Posted: Wed Feb 15, 2006 2:43 pm
by Eldred
It's thinking outside the box. Most of the time these types of questions are posed to see ones thought prosses, not just to see if they can do math in their head.
Posted: Wed Feb 15, 2006 2:53 pm
by Yamori
6^4 (1296)
Square of 1296= 36
36-8 = 28
28-2 = 26
DAMN
Posted: Wed Feb 15, 2006 2:54 pm
by Menlaan
I think Eldred got it. Thanks!
Yamori, that was close!
Menlaan
Posted: Wed Feb 15, 2006 2:55 pm
by Harrison
Posted: Wed Feb 15, 2006 2:57 pm
by Yamori
Harrison wrote:Yamori wrote:28-2 = 25
yeah im cracked this morning, roffle
Pretty silly that I did the exponents and squares right but did kindergarten subtraction wrong. ><
I blame... the sea.
Posted: Wed Feb 15, 2006 2:58 pm
by Tacks
Well I'm more of a math thinker and this was the closest I could come
8 X square root of 6 + square root of 2 + 4 = 25.0101
Posted: Wed Feb 15, 2006 3:08 pm
by Yamori
Actually, I dunno if exponents technically work for this - it does use multiples of the same number.
Posted: Wed Feb 15, 2006 3:10 pm
by Eldred
The problem is 25 is a rational number and the Square root of 2 and 6 are irrational numbers. Therefor 25.01013105463851983437996072421 non terminating none repeating number. And Rational Numbers can't be Irrational Numbers.
Posted: Wed Feb 15, 2006 3:10 pm
by Tacks
Well I don't know how technical it needs to be. In my field of work 25.01 = 25.
I don't expect this to be what they're looking for at all, this is just what I could come up with :P
Posted: Wed Feb 15, 2006 3:14 pm
by Eldred
Zanchief Returns wrote:Eldred wrote:2+8= 10
1+0= 1
4*6= 24
1+24= 25
lame
Lets see you post something then cock goblin.
Posted: Wed Feb 15, 2006 3:35 pm
by Tacks
Also technically you never said you can't use OTHER number, you just said you can only use 2,4,6 and 8 once. So according to your question you could do:
8 x 6 divided by 4 + 2 +11=25
or any other combination really
Posted: Wed Feb 15, 2006 3:40 pm
by Diekan
Tacks wrote:Well I don't know how technical it needs to be. In my field of work 25.01 = 25.
I don't expect this to be what they're looking for at all, this is just what I could come up with :P
Since when did cash registers stop calculating coin change?
Posted: Wed Feb 15, 2006 3:51 pm
by Tacks
ya perhaps i should have been a complete and utter mindless meathead with no skills at all and went into the military instead of living on the streets. nah, i chose college and getting high pay for minimal amounts of work.
PS: thanks for displaying your lack of intelligence by your only post here and thus proving my point~