Dude.. We have only one bag with 1.1 gram coins...For this take 1 coin from first bag..then 2 coins from second bag ..and so on..

Now weight that and compare with is original Weight u will find which bag contain forgeries.

Example : let we taken coins 1 , 2,3,4,5,6,7,8,9,10

now u know that actual weight is 55 Grams but let say when u weight that it comes 55.2 gram than u can directly say that 2nd bag is with forgeries.