Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

Hi all,

Here is a YOB/YOP-type puzzle (some of you know what that means) that I'd forgotten about, and that stefy asked if I had any more of.

I found it some time ago on another forum (now closed) and solved it, but instead of posting my answer there I replied with a puzzle of my own, the solution to which proves I solved the *Chocolate!* puzzle. So for anyone to know that I'd solved it, they had to solve mine too (which no one ever did).

*Chocolate!*:

Jake and Marie are on their way to visit Grandma, who lives at the end of the valley. It's her birthday, and they have a basket with chocolate bars they bought to give her.

Between their house and Grandma's they have to cross 7 bridges, and (it goes without saying) there is a troll under every bridge! The trolls, quite rightly, insist they each be paid a 'troll toll' before Jake and Marie can cross their bridge, the toll being half the number of chocolate bars in the basket; but they're kind trolls, and each, in turn, returns a single chocolate bar to the basket.

How many chocolate bars do Jake and Marie leave home with to arrive at Grandma's with 2 chocolate bars?

My puzzle:

By ascribing a numeric value to the letters of "Jake", "Marie" and "troll" based on each letter's position in the alphabet (ie, a=1, b=2......z=26) and then adding them together, a value can be obtained for each name.

You will then find that the reverse of the difference between the numeric value of "troll" and the sum of the product of the digits of the numeric value of "Jake" and the product of the digits of the numeric value of "Marie", multiplied by the sum of the digits of the prime factors ("PF") of the afore-mentioned product sum, divided by the sum of the digits of the difference between the number comprising the PFs (arranged in ascending prime factor order) and its reverse, less the sum of twice one less than half the quotient and the two bars left over for Grandma, equals the total number of troll-toll chocolate bars.

So I guess the question is this:

Can you verify that I actually solved the *Chocolate!* puzzle?

*EDIT 23/5/13: In 'My puzzle', replaced the two clauses after "and its reverse" (near the end) with "less the sum of twice one less than half the quotient and the two bars left over for Grandma"...to remove ambiguity.*

*Last edited by phrontister (2013-05-22 21:03:41)*

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

Hi phro

Thanks for posting this!

For the first puzzle: When do the trolls return the chocolates?

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

Offline

**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,465

It says "each, in turn" thus I presume that they return one chocolate bar immediately after taking the toll.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

But, that just means they return them in the order they take them, not when.

I am asking because, if they return a chocolate immediately, I get a weird

.Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

Offline

**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,465

Well yes, that seems too easy if they take one and return one.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

Khm, you do mean take a half and return one, don't you?

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

Shivamcoder3013 wrote:

It says "each, in turn" thus I presume that they return one chocolate bar immediately after taking the toll.

Correct. The first troll takes the entire toll required for their bridge, and then, because they're so kind, immediately returns one chocolate bar to the basket. Jake and Marie then move on to the next bridge, and the toll process is repeated...and so forth, until all bridges are crossed.

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,465

Yes, but assuming they start with 2, take one (half of two) and return one immediately. That probably is not the case.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

It is good that the other puzzle is there as a check.

Here lies the reader who will never open this book. He is forever dead.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

Yes...for the same reason that I included the solution check in 'bobbym's YOB'.

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

Hi phro

*Last edited by anonimnystefy (2013-05-22 03:16:48)*

Here lies the reader who will never open this book. He is forever dead.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

Hi stefy,

Spot on!

I corrected an error in the second line of the second paragraph in my first post, and also improved the wording of the "reduced to..." part of the puzzle to "reduced to the cube root of the sum of the digits of that division".

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

The "reduced to..." part is still a bit ambiguous. At first I thought that what I need is x-cbrt(x).

Here lies the reader who will never open this book. He is forever dead.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

I agree...which is why I amended the wording (particularly after seeing your first answer before your edit). It's always worried me a bit, but as I understood what I meant there I managed to convince myself that it was ok. I think I'll do something about that...it just needed someone like yourself to confirm my misgivings about it and to prompt me into action.

And maybe that's why my puzzle was never solved on that dead forum!

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

Hi phro

Yeah, the wording needs a fix.

And, speaking of words, do you, maybe, remember those old girthbruins' threads about finding what's in common for a set of words?

*Last edited by anonimnystefy (2013-05-22 10:34:05)*

Here lies the reader who will never open this book. He is forever dead.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

Yes, I do. They were excellent puzzles and I quite enjoyed them.

There was one puzzle (I forget which one now) that I didn't manage to solve, which bothered me for ages and I've tried many times since the thread died to try and solve it. Maybe I'll look at it again, now that you've raised its spectre.

Am getting ready for work, and really must go now...

*Last edited by phrontister (2013-05-22 10:39:28)*

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

The problem with those puzzles is I have no idea where to even start. I have never solved one, and I don't know where to find simpler ones.

See you later!

Here lies the reader who will never open this book. He is forever dead.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

anonimnystefy wrote:

Yeah, the wording needs a fix.

Fixed. (see post #1)

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

But, the cube root version was fine. It just needed rewording.

Here lies the reader who will never open this book. He is forever dead.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

True, and I did a reword with that in it. But while I was at it I also thought up about 3 other alternatives for that ending (there are many, of course), none of which featured the cube root...and out of the lot (including the cube root version) the one I posted was my favourite.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

I do not see "cube root" anywhere in the new puzzle...

Here lies the reader who will never open this book. He is forever dead.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

The reword with the cube root in it was only in my head, composed while I was at work. I didn't write it down. So was the final version that I liked best, which I thought of while driving and recorded into my mobile via its sound recorder in case I forgot it.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

Using a phone while driving?

Here lies the reader who will never open this book. He is forever dead.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,820

Well, it was a choice of either chancing to get an enormous fine or forgetting the fix...and I opted for the former, of course. Trying to write it down while driving would have been worse.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 14,885

Now, that is a true puzzler!

Here lies the reader who will never open this book. He is forever dead.

Offline