Washi co September 2018

Hello jhon I have a small doubt regarding washi co Here it is we found the exchange rate between Ard and yen It's 0.70-0.73 / i¥ We receive cash flows in the Ard so as we are in Japan we convert Ard to yen, so when we approach the back to sell the Ard , then bank tells us give me 0.73 Ard and I'll give you 1 ¥ is this logic correct? If so then why did we take 0.70 Ard as the exchange rate ?? Please please please please jhon help me out with this