How much money did Mr Wang lose?

Question

Mr Wang sells shoe.
A pair of shoe costs $20 and its selling price is $30.
A customer bought a pair of shoe and paid with a $50 note.
Mr Wang didn't have change so he went to his neighbor to break it into small notes.
He returned $20 to the customer.
The next day, Mr Wang's neighbor realized that the $50 note was a fake.
Mr Wang compensated his neighbor $50.

Question:
How much money did Mr Wang lose?

Answer 1

Mr Wang lose = $40
He lose $20 of shoes and $20 which he returned to the customer
And talking about selling price $30 and cost price $20,In these $10 was his profit not any loss
So answer is $40

Answer 2

He lost Rs twenty

Comments

Whats the logic ??