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Simple question gets a complicated answer (Posted on 2010-05-02) Difficulty: 4 of 5
Bob, when addressing my indiscreet question regarding his and his wife's ages, came up with the following answer:

"Take my age now, multiply it by my age on the wedding day, then subtract my wife's present age multiplied by her age on our wedding day.
If then you add the difference between her present age multiplied by my age on the wedding day and my present age multiplied by her wedding day age ( making no errors in your proceeding) you should end up with 511 as a result."

Since Bob knew (and rightly so) that I was ignorant about how long they were married, he assumed that either his secret will stay undisclosed forever or that I will humbly request additional data.

How wrong he was!

Without calculator, just pen and paper and 10-15 minutes of your time you will solve it too.

I bet programming is not needed.

See The Solution Submitted by Ady TZIDON    
Rating: 3.0000 (2 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Hints/Tips re: Solution..... slightly modified | Comment 3 of 4 |
(In reply to Solution by hoodat)

Please pay attention:
...."If then you ADD the difference between her present age multiplied by my age on the wedding day and my present age multiplied by her wedding day age ( making no errors in your proceeding) you should end up with 511 as a result."

The error of changing - into plus was a typo error,you continued correctly and got (x + y + 2a)(x - y) = 511   which is right.

Now x + y + 2a= x+a+y+a= sum of their present ages
and x-y= difference between  their present(or anytime) ages

X+Y= 73    X-Y=7 ;     X,Y RELATING TO PRESENT AGES.


Rem:  Choosing X , Y,and t    or X , X-d and t makes t dissappear
at the earliest stages. With your choice  of the uknown variables you did not realize that at  some stage you introduced a redundant entity, adding a square of a negative a = 33 - y, and from then on you were dealing with a distorted equation. <br>
If you are not convinced, check every stage of
 our reasoning by inserting numbers. <br>
You will find that the duration of the couple's marital state stays undisclosed.

 


  Posted by Ady TZIDON on 2010-05-03 01:03:09
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