Which sack of coins holds the gold?

[Jonmo1]

The rules don't say you must actually use the scale.

If there are 100 coins in each bag, then the bag with the gold is 6.25 Pounds heavier than the rest.
You could tell the difference by simply lifting each bag and choosing which one is heavier.

 

[Wookiee]

Yep. As much as I like working with pure logic and it's creativity thru coding etc, real world is not always so binary. May sometimes require common sense thinking for the best results.

My first thought when seeing the original post was: I love logic puzzles, but what's that doing in an Excel forum? But after reading through the thread, I think it is a great way to illustrate principles used in VBA coding.

I've found that coding automated tasks in VBA is not nearly as difficult as predicting all the ways in which the code might go south and trying to include error handling for each possible scenario.

 

[Joe4]

I love logic puzzles, but what's that doing in an Excel forum?

That is why it is posted to the "Lounge" instead of the "Excel Questions" forum.
(note the description of the "Lounge" forum).

 

[Wookiee]

That is why it is posted to the "Lounge" instead of the "Excel Questions" forum.

Thanks for explaining. That was my first post and I had arrived at that thread via the "Search New Posts" link at the top of the site. I'll keep that in mind next time.

 

[Joe4]

Thanks for explaining. That was my first post and I had arrived at that thread via the "Search New Posts" link at the top of the site. I'll keep that in mind next time.

No worries. That Search functionality has tripped up many a veteran member too, in that many have responded to Access questions with Excel answers (not realizing that the question is actually in the Access forum, not the Excel forum).

BTW, welcome aboard! Hope you find this site useful!

 

[dfida]

But if the question is put slightly differently - "How can you separate the pure gold coins from the fakes ?" then Davesweep's suggestion won't necessarily do it, without some refinement.

I am not sure if this qualifies as "using the scale only once", but let's say it's one of those old-time scales where you put weights on one side and the thing you want to weigh on the other side. In this case, instead of using weights, you put 5 bags on one side and 5 bags on the other side.

The side with the real gold will be heavier, and will dip down. Then you proceed to remove one bag from each side. When you remove the real-gold bag, the scale will balance. Now you know which bag has the gold.

 

[chuckchuckit]

I've found that coding automated tasks in VBA is not nearly as difficult as predicting all the ways in which the code might go south and trying to include error handling for each possible scenario.

Welcome to the board Wookiee.

Ah yes, that can be the longer term end result of good code = less bugs etc. Then there is often that tradeoff between getting the job completed (Production) -vs- doing the extra time and effort especially in places needed where no one may ever notice right away (Quality).

It can be difficult enough to just learn something new (I'm still somewhat new to VBA). But if the mindset starts off as "Just do what looks good or gets instant results (Production)", then the resulting lower quality and bigger problems will eventually show up later. If that mindset happens a lot or becomes accepted as status quo, then a lot of other things too can be affected and start going downhill, and then become not so easy to fix later. Like it is said - "An ounce of prevention is worth a pound of cure."

Sometimes takes some unhurried thought before even starting some things, to figure the realistic balance in any tradeoff (such as: Production/Quality).

 

[Err]

There is also no rule about how many gold sacks you can take. Why not take them all?

Even the fake gold coins have a value (it is assumed) so take them all.