Money bags

This puzzle is different from the other riddles with coins.

You have 10 bags of gold coins (you wish :)).

One of your servants who were responsible for transport of the money wanted to trick you. He took one of the money bags and filed away one gram of gold from each coin. One coin normally weighs 10 grams.

Can you figure out in one scaling which bag contains lighter coins – which servant should be fired – using digital scales (shows the exact weight of an item)?


Why do you think there are bags and not single coins?


You put one coin from first bag on the scales, two coins from the second one, three form third, etc... How many grams is the scaled weight lower than it should be shows which bag has the "modified" coins inside. (If three grams are missing it means that it was the third bag)