Those who are saying that answer can be 2000 or 1800 don't seem to realise that the 800 given to lady was actually the one she got from shopkeeper 2....

1st step the lady took was to get the fake not changed from Shopkeeper 2. 2nd step she took was to give 200 money for 200 goods earning shopkeeper 1...

No, No, No. The answer is 1000. As the the loss for Shopkeeper 1 in the first transaction was nothing as he gave 200 worth of real goods for 200...

Lady brings in 1000rs fake note. She gets a change from shopkeeper 2. Gives 200 REAL money to Shopkeeper 1 and gets 200 worth of goods in return. Right now,...