i borrowed from someone Caanadian money is there any problem in paying him back in US Dollars?
Answer:
At the time of writing, 100 Canadian Dollars are worth around 96.5 USD. This means that somebody who borrowed 100 Canadian Dollars may not pay back 100 USD, because this would involve a prohibited payment of ribis. However, provided the lender agrees, it is permitted to pay back the equivalent sum in USD. It should be noted that the actual loan of Canadian Dollars (in exchange for the return of Canadian Dollars) in the US is only permitted when the borrower possesses Canadian Dollars (one is sufficient).