Logic: Three coin bags

Rafael will also give 100 tokens to the first person who posts the correct solution to the following problem:

Think about three leather bags in which thousands of gold coins can be found. Two of the bags contain false coins and the other one contain the good ones. Think the way to solve the problem using the precision scales you own only once.

[Benny]

Did you forget to mention that real gold coins weigh 10 ounces and fake gold coins weigh 9 ounces? (or am I thinking of the wrong puzzle?)

Anyway, you take 1 coin from the first bag, 2 from the second bag and 3 from the third bag. Take all the coins you removed and weigh them in one go.

First bag is real if weight is 55 (=1(10) + 2(9) + 3(9)) ounces
Second bag is real if weight is 56 (=1(9) + 2(10) + 3(9)) ounces
Third bag is real if weight is 57 (=1(9) + 2(9) + 3(10)) ounces

Well done Benny
You should have recieved your 100 tokens

_Congratulations!
Rafael