Yep, that's it.

>Ok, take one coin from the second bag and 2 coins from the third bag (you can use 1 from the first, 2 from the second, 3 from the third). Weigh them...
>
>>Nope.
>>
>>>Can we put one bag on one scale and another on another scale?
>>>
>>>>You have three bags of gold coins and 1 penny.
>>>>
>>>>You know that in two of the bags contains real gold but the other containts "Fools Gold".
>>>>
>>>>In the bags with real gold, each coin weighs exactly one pound.
>>>>In the bag with "Fools Gold", each coin weighs exactly one pound and one ounce.
>>>>
>>>>You have one penny for a penny scale. How would you determine which bag contains the "Fools Gold"?