Brain teaser/ math expert help needed!!!!

[geosheets]

Quote:
should have added... 13 years ago, smith was 39 and jones 26

 

[FireTigeris]

Quote:
ok, I was making it less complicated then it was - I should have known not to get a fraction answer.

 

[geosheets]

Quote:
should have added... 13 years ago, smith was 39 and jones 26

duh... didn't see someone already posted the answer while I was calculating...

 

[goldenluver]

you forget,that means that he isnow that exact amount older that Jones is now.
the closest I come to it is
54 and 37

1/2 of 37 is 18.5

and 37 + 18 = 54

 

[FireTigeris]

Quote:
should have added... 13 years ago, smith was 39 and jones 26

duh... didn't see someone already posted the answer while I was calculating...

It's ok, I did it wrong so everyone could see.

You try doing math on two different cold medications.

 

[WriterofWords]

Good site for help:
http://www.algebra.com/algebra/home...rational-expressions.faq.question.390230.html





Smith and Jones combined age is 91. Smith is twice as old as Jones was when Smith was as old as Jones is now.
Smith is obviously the older and the age gap is d. Smith’s age is s and Jones’ age is j.
So we have two equations:
s + j = 91…………. (1)
s - d = j …………... (2)
Smith is twice as old as Jones was when Smith was as old as Jones is now, so reducing Smith’s age by d to make Smith what Jones’ age was gives us
s - 2d = j - d ……... (3)
Now j - d is what Jones’ age was d years ago which means that Smith’s age is now is twice that.
Therefore we use (3) to get
s = 2(s - 2d) …….... (4)
Rearranging (4): s = 2s - 4d gives 4d = s or d = s/4
Substituting this into (2): s - s/4 = j gives 3s/4 = j
Now substituting this into (1) gives s + 3s/4 = 91
7s/4 = 91; s/4 = 13; s = 52; j = 39.
So, Smith is 52 and Jones is 39; 13 years ago when Smith was 39 Jones was 26.
Check the details:
52 + 39 = 91
When Smith was 39, Jones was 26; Smith is now 2 times 26 = 52.
I hope this helps.

 

[lotzahenz]

Yeah, I think we have the right answer. I concur. I could not get it at this hour, too tired (yep, that was it).

 

[stanglover2001]

After much algebra my darling husband an Electrical/Mechanical Engineer (who has had much algebra/calculus/diffrential equations/matrix algebra... etc with all A's) his answer is Jones = 39 and Smith = 52. He's explaining it to me now so I can give you all his equations.

ETA: Someone gave enough in an earlier post of the same equations so I'll save me some time and not bother

 

[Cindiloohoo]

I GUESStimated, because I'm too sleepy for equations and I was only a year off

 

[Spookwriter]

What we really want to know is why Sherlock Holmes needed
to know the age of the criminals?