Dan,

What's "a penny scale"?

>Part 1.
>
>You have 10 bags of 1000 gold coins each.
>One of the bags is fake gold and each coin weighs 1.1 lb.
>The other bags contain real gold and each coin weighs 1.2 lb.
>
>You have one penny to use on a penny scale.
>( No tricks, using gum and a string to pull the penny back out :) )
>
>How can you weigh the gold in such a way that you can determine which bag has the fake gold.
>
>
>Part 2
>
>This problem is the same as above, but there is at least one bag of real gold. There could be as many as 10 with real gold.
>
>How do you weigh the gold in such a way to determine which bags have the real gold?