Math problem for a friend...

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It's been 2 years since I took any sort of math, and 4 since I took anything close to this, yet this girl still asks for my help...whatever. Anyway, here is the problem.

Friend (4:31:41 PM): if you have a basket of eggs
Friend (4:31:49 PM): and you subtract 2... you're left with 1
Friend (4:31:59 PM): if you subtract 3... you're left with 2
Friend (4:32:06 PM): subtract 4... you're left with 3
Friend (4:32:13 PM): subtract 5... left with 4
Friend (4:32:20 PM): subtract 6... you're left with 5
Friend (4:32:28 PM): but if you subtract 7... you're left with 0
Friend (4:32:36 PM): how many did you originally start off with
Friend (4:32:44 PM): answer is between 100 and 150

I'm not even sure how to continue, because when I write it down, X = 3,5,7,9,11...then 7 again. Is it some sort of function or what?

HELP ME FIGURE THIS ONE OUT ATOT
 
H

HonkeyDonk

Diamond Member
Oct 14, 2001
4,020
0
0
Originally posted by: FallenHero
It's been 2 years since I took any sort of math, and 4 since I took anything close to this, yet this girl still asks for my help...whatever. Anyway, here is the problem.

Friend (4:31:41 PM): if you have a basket of eggs
Friend (4:31:49 PM): and you subtract 2... you're left with 1
Friend (4:31:59 PM): if you subtract 3... you're left with 2
Friend (4:32:06 PM): subtract 4... you're left with 3
Friend (4:32:13 PM): subtract 5... left with 4
Friend (4:32:20 PM): subtract 6... you're left with 5
Friend (4:32:28 PM): but if you subtract 7... you're left with 0
Friend (4:32:36 PM): how many did you originally start off with
Friend (4:32:44 PM): answer is between 100 and 150

I'm not even sure how to continue, because when I write it down, X = 3,5,7,9,11...then 7 again. Is it some sort of function or what?

HELP ME FIGURE THIS ONE OUT ATOT
Click to expand...

you like this girl huh?
 
C

chuckywang

Lifer
Jan 12, 2004
20,133
1
0
Originally posted by: FallenHero
Well now don't I feel dumb...
Click to expand...

eh, simple number theory. I love number theory cause the problems are easily understood by all, but the theory is complex and beautiful.
 

Originally posted by: HonkeyDonk
Originally posted by: FallenHero
It's been 2 years since I took any sort of math, and 4 since I took anything close to this, yet this girl still asks for my help...whatever. Anyway, here is the problem.

Friend (4:31:41 PM): if you have a basket of eggs
Friend (4:31:49 PM): and you subtract 2... you're left with 1
Friend (4:31:59 PM): if you subtract 3... you're left with 2
Friend (4:32:06 PM): subtract 4... you're left with 3
Friend (4:32:13 PM): subtract 5... left with 4
Friend (4:32:20 PM): subtract 6... you're left with 5
Friend (4:32:28 PM): but if you subtract 7... you're left with 0
Friend (4:32:36 PM): how many did you originally start off with
Friend (4:32:44 PM): answer is between 100 and 150

I'm not even sure how to continue, because when I write it down, X = 3,5,7,9,11...then 7 again. Is it some sort of function or what?

HELP ME FIGURE THIS ONE OUT ATOT
Click to expand...

you like this girl huh?
Click to expand...

I find her voice annoying. Besides, I have a g/f...but its nice to help out, and maybe I'll get dinner paid for (this one is loaded.)
 
Kyteland

Kyteland

Diamond Member
Dec 30, 2002
5,747
1
81
The answer is 119. Proof in a bit.

The number you are looking for is X. 100<X<150. Your rules set up these equations:
  • 1) X-2*A = 1
    2) X-3*B = 2
    3) X-4*C = 3
    4) X-5*D = 4
    5) X-6*E = 5
    6) X-7*F = 0
By rule 6) the only numbers that fit are in the set {105, 112, 119, 126, 133, 140, 147}
By rule 5) {101, 107, 113, 119, 125, 131, 137, 143, 149}
The intersection of these sets is: {119}
You can then test that 119 is also in the sets for rules 1), 2), 3) and 4)
 
N

notfred

Lifer
Feb 12, 2001
38,241
4
0
Why can't people write damned questions that make sense?

You have a number X, all of the following are true:

X - 2 = 1
X - 3 = 2
X - 4 = 3
X - 5 = 4
X - 6 = 5
X - 7 = 0

100 < X < 150

Is that what this question is supposed to mean or not?
 
C

chuckywang

Lifer
Jan 12, 2004
20,133
1
0
Originally posted by: notfred
Why can't people write damned questions that make sense?

You have a number X, all of the following are true:

X - 2 = 1
X - 3 = 2
X - 4 = 3
X - 5 = 4
X - 6 = 5
X - 7 = 0

100 < X < 150

Is that what this question is supposed to mean or not?
Click to expand...

Originally posted by: chuckywang
replace "subtract" with "keep on subtracting".
Click to expand...

 
Kyteland

Kyteland

Diamond Member
Dec 30, 2002
5,747
1
81
Originally posted by: aves2k
Originally posted by: chuckywang
Here's the proof: 119 satisfies all the conditions. QED.
Click to expand...
LOL!
Click to expand...
But it doesn't explain how to do the problem, so they learned nothing. The point is to teach them so that they can do it themselves next time.
 
Aves

Aves

Lifer
Feb 7, 2001
12,232
30
101
Originally posted by: notfred
Is that what this question is supposed to mean or not?
Click to expand...

No. Take a look at the post by blahblah99. I was confused at first also.
 
N

notfred

Lifer
Feb 12, 2001
38,241
4
0
Originally posted by: Kyteland
Originally posted by: aves2k
Originally posted by: chuckywang
Here's the proof: 119 satisfies all the conditions. QED.
Click to expand...
LOL!
Click to expand...
But it doesn't explain how to do the problem, so they learned nothing. The point is to teach them so that they can do it themselves next time.
Click to expand...

No, the point is to get free dinner.
 
N

notfred

Lifer
Feb 12, 2001
38,241
4
0
Originally posted by: aves2k
Originally posted by: notfred
Is that what this question is supposed to mean or not?
Click to expand...

No. Take a look at the post by blahblah99. I was confused at first also.
Click to expand...

Yeah, I get it now, but the question doesn't say that at all.
 
MartyMcFly3

MartyMcFly3

Lifer
Jan 18, 2003
11,436
29
91
www.youtube.com
Originally posted by: Kyteland
Originally posted by: aves2k
Originally posted by: chuckywang
Here's the proof: 119 satisfies all the conditions. QED.
Click to expand...
LOL!
Click to expand...
But it doesn't explain how to do the problem, so they learned nothing. The point is to teach them so that they can do it themselves next time.
Click to expand...

chuckywang explained it. The girl didnt write the question correctly or worse, her teacher didnt teach it to her properly. Thread over.
 
Aves

Aves

Lifer
Feb 7, 2001
12,232
30
101
Originally posted by: Kyteland
Originally posted by: aves2k
Originally posted by: chuckywang
Here's the proof: 119 satisfies all the conditions. QED.
Click to expand...
LOL!
Click to expand...
But it doesn't explain how to do the problem, so they learned nothing. The point is to teach them so that they can do it themselves next time.
Click to expand...

Perhaps but it doesn't make his smartass response any less funny. :p
 
Kyteland

Kyteland

Diamond Member
Dec 30, 2002
5,747
1
81
Originally posted by: notfred
Originally posted by: Kyteland
Originally posted by: aves2k
Originally posted by: chuckywang
Here's the proof: 119 satisfies all the conditions. QED.
Click to expand...
LOL!
Click to expand...
But it doesn't explain how to do the problem, so they learned nothing. The point is to teach them so that they can do it themselves next time.
Click to expand...

No, the point is to get free dinner.
Click to expand...
This is why I'm single right now. :(

:beer::p
 
S

Spencer278

Diamond Member
Oct 11, 2002
3,637
0
0
Originally posted by: blahblah99
119 mod 2 = 1
119 mod 3 = 2
119 mod 4 = 3
119 mod 5 = 4
119 mod 6 = 5
119 mod 7 = 0
Click to expand...

Maybe I'm reading the question wrong but when did subtract become mod?
 
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