What happened? 317 people die...

[scubapolly]

Ok split into 3 groups.
#1 Weight 4 vs 4. If they are the same weight you know the coin isn't in one of those.So you do 3 of the coins from the original weighing as your "controls" and weigh 3 of the remaining coins. If those are the same you know the coin you didn't weigh is the counterfit, weigh it against any one of the original coins to see if it is heavier or lighter. If the 3 vs 3 results in an imbalance (if it is heavier or lighter, you now know which direction the coin goes). Of the group that is off you weigh 1 vs 1. If they balance # 3 is the counterfeit. If they don't balance which ever one is off in the proper direction is the counterfit.

#2 if in your 4 vs 4 you have an imbalance. You know that the 4 coins that were set asside does not contain a fake. From here I am stumped because you don't know which side of the original weighing has a fake. So I need an extra weighing in order to figure it out.

 

[scubafool]

If the 4 vs 4 weighing contains an inbalance, note which way the imbalance is. Remove 2 coins from one of the sides (let's pick the right side), and take one coin from the left and put it on the right. Now, if the scale balances, you know that one of the two coins that you removed from the right side is counterfeit, and you can use your third weighing to figure that out. If the imbalance stays the same, you know it is one of the two coins on the right side, and you use your third weighing to figure that out. If the imbalance changes, you know that the coin that you moved from the left is the culprit.

 

[scubapolly]

I was thinking something along those lines, but just couldn't get it.

 

[Nay]

I love the birds on a fence one! That was one my grandpa used on me all the time.

All of my childhood, I couldn't wrap my head around this one, even when I was told them answer. Obviously I get it now...

"What weighs more, a pound of rocks or a pound of feathers"

The answer is easy but I just couldn't get over the rocks/feathers things.

Can anyone explain the burying the arm that came in the box thing?

 

[scubapolly]

A pound of anything weighs the same.

 

[Nay]

A pound of anything weighs the same.

Of course it does, but my brain could NOT let go of the fact that rocks weigh more than feathers!

 

[fairybasslet]

Ok, here's a really tricky one. If a mom gives her teenage son $20 at the beginning of the week to buy lunch, and he then says he needs to buy a $10 CPR book. But the mom doesn't have a $10 bill so she gives him another $20. He then says he needs $5 for his CPR card cause he passed the test :35: When the mom says he has an extra $10 so buy the card with that, he huffily replies "OK I'll buy the card with my own money, but I need $11 for a stethoscope." How many years in jail will the mom get for :whack: or should she just :bonk:

Clue, she had a horrible headache in the morning, it finally went away after working out lunch time, and after a phone conversation with son, it came back.

 

[wilkie]

About the arm in a box thing; Any chance it was a prosthesis??

 

[mike_s]

Ok, here's a really tricky one. If a mom gives her teenage son $20 at the beginning of the week to buy lunch, and he then says he needs to buy a $10 CPR book. But the mom doesn't have a $10 bill so she gives him another $20. He then says he needs $5 for his CPR card cause he passed the test :35: When the mom says he has an extra $10 so buy the card with that, he huffily replies "OK I'll buy the card with my own money, but I need $11 for a stethoscope." How many years in jail will the mom get for :whack: or should she just :bonk:

Clue, she had a horrible headache in the morning, it finally went away after working out lunch time, and after a phone conversation with son, it came back.

Tell the kid that if he keeps this up, he will need CPR for sure.

 

[Nay]

Ok, here's a really tricky one. If a mom gives her teenage son $20 at the beginning of the week to buy lunch, and he then says he needs to buy a $10 CPR book. But the mom doesn't have a $10 bill so she gives him another $20. He then says he needs $5 for his CPR card cause he passed the test :35: When the mom says he has an extra $10 so buy the card with that, he huffily replies "OK I'll buy the card with my own money, but I need $11 for a stethoscope." How many years in jail will the mom get for :whack: or should she just :bonk:

Clue, she had a horrible headache in the morning, it finally went away after working out lunch time, and after a phone conversation with son, it came back.

Sorry to hear that your head is about to explode.

Do you think he's laugh if you told him that since he used him own money for the CPR card, here's a dollar to use with the $10 overpayment from the CPR book for the stethoscope?