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        riddles >> easy >> How Old Is Pastor Ulrik?
        
(Message started by: wowbagger on Feb 28^th, 2003, 2:07am)

Title: How Old Is Pastor Ulrik?
Post by wowbagger on Feb 28^th, 2003, 2:07am

Here's a riddle related to Daughters' Ages (http://www.ocf.berkeley.edu/~wwu/riddles/hard.shtml#daughtersAges):

Jensen was in the local pub to sample the atmosphere, when he overheard the bartender and the local school teacher talking.
The bartender said "Pastor Ulrik will be visited by three women this weekend. Can you work out how old they are, if you know that their ages multiplied together is 2450, and that together they are as old as you are..."
"No, I can't" said the teacher after deep consideration (and a pilsner).
"Of course you can't - but, if I tell you that the oldest woman is older than pastor Ulrik you should be able to work it out..."
At this point Jensen thought "I can work that out", but when he came up to the bar he found out that it was not as easy as he thought. The problem wasn't how old the women were, but how old Pastor Ulrik was...

Title: Re: How Old Is Pastor Ulrik?
Post by BNC on Feb 28^th, 2003, 11:51am

Let me give Jensen a hint: Pastor Ulrik is [hide]49[/hide] years old. He should be able to tell how old the women are.

Title: Re: How Old Is Pastor Ulrik?
Post by wowbagger on Feb 28^th, 2003, 12:00pm

Correct.

Title: Re: How Old Is Pastor Ulrik?
Post by prince on Feb 28^th, 2003, 12:03pm

Pastor Ulrik is 15 years younger than the schoolteacher.

Title: Re: How Old Is Pastor Ulrik?
Post by prince on Feb 28^th, 2003, 12:06pm

Aargh! BNC, you posted while I worked it out! Guess I need to be quicker.

Title: Re: How Old Is Pastor Ulrik?
Post by udippel on Mar 1^st, 2003, 9:52am

Is there any thread to enlighten me about this 'Aargh' ??

I rather say oops and don't get the point. How would the teacher know - and worse - why is this *the* solution ?? Of course, the three ages have to multiply to 2450:
A * B * C = 2450
which excludes quite a few A, B, C
All have to add up to a reasonable age:
A + B + C << 1000
But for the rest ???

Why can Ulrik not be at 48, the "middle-aged" (sorry, ladies !!) woman 25 ? Which would result in the elder lady to be 49 and the younger to be at 2 ??

The only argument might be the age of the teacher. Retirement here is at 55; I'd know some countries where this stands at 60.
No luck here with either combination; but some teachers work beyond their retirement; it seems; in Riddle-Land ... !

Title: Re: How Old Is Pastor Ulrik?
Post by BNC on Mar 1^st, 2003, 11:14am

udippel,

You have two bits of information:
1. The multiplication of all three ages is 2450, and
2. Knowing the sum didn’t help the schoolteacher know the ages (hidden assumption: schoolteachers know how to “do” math and have some use of common logic. Not always true where I live, but in the riddle land it’s ok).

OK, let’s look at 2450. Break into its factors, and you get 2, 5, 5, 7, 7. The three ages must be made from these, and only these numbers (usage of 1 is allowed, though). Run all possible combinations (including ages of 1 year old) and you get 20 possible unique combination.
Now, look at the sum of every possible age combination. Remember: knowing the sum didn’t help the teacher. If the ages would indeed be, as in your example 2, 25, 49, then by knowing that the sum is 76, the teacher may know the ages immediately. So we need to look for (at least) two age combinations that yield identical sum.
Scan through the combinations. There is only one possible pair that match both requirements (multiplication is 2450, identical sum): {5, 10, 49} and {7, 7, 50}. Now, how to choose between them?

In the original riddle (referred to by Wowbagger), the solution came from the last sentence: “oh sorry, the oldest one just started to play the piano”. There, one of the two combinations was of a younger sibling, and older twins. Knowing that one is older provided the extra information bit required.

In this riddle, the point is "Of course you can't - but, if I tell you that the oldest woman is older than pastor Ulrik you should be able to work it out...". Look at the two possibilities. The older one is either 49 or 50. Thus, pastor Ulrik must be 49: any younger, and both possibilities would fit. Older, and none would fit.

Summary: the ages are 7, 7, 50, and pastor Ulrik is 49 years old.

The only (disturbing ;) ) question remaining – Wowbagger, do you usually refer to 7 year old children as “women” ? :D

Title: Re: How Old Is Pastor Ulrik?
Post by wowbagger on Mar 3^rd, 2003, 2:18am

on 03/01/03 at 11:14:32, BNC wrote:

udippel,

You have two bits of information:
1. The multiplication of all three ages is 2450, and
2. Knowing the sum didn?t help the schoolteacher know the ages

I do like riddles where the extra information of not knowing something leads to a solution. :)

Quote:

(hidden assumption: schoolteachers know how to ?do? math and have some use of common logic. Not always true where I live, but in the riddle land it?s ok).

:D

Quote:

The only (disturbing ;) ) question remaining - Wowbagger, do you usually refer to 7 year old children as ?women? ? :D

Of course, I could try to convince you that it's only for the sake of not making the riddle too easy... ok, somehow I knew you would't buy that.:-[
Um, I declare that any resemblance to actual events, places or persons is strictly coincidental.
For the very most insistent: No, I usually don't. ;)

Well, I don't really know what you have in your (possibly filthy ;)) mind, BNC, but in my country it would most probably be forbidden.
Nice delineation of the train of thought, by the way.

Title: Re: How Old Is Pastor Ulrik?
Post by udippel on Mar 3^rd, 2003, 9:16am

Of course you're so right ! - The devil's in the detail: to me the wording was somewhat unclear and then I'm not too bright. I actually missed the turn with the multiple solutions "any younger, and both possibilities would fit. Older, and none would fit. "
Thanks for the explanations !!