USD/DM = (1.6640+0.0203)/(1.6650+0.0205) =1.6843/1.6855.

(1) For immediate payment, considering currency exchange, DEM quotation should be used instead, and the quotation is1000 *1.6650 =166.50 DEM.

(2) Payment after three months, considering the currency exchange cost and the risk of exchange rate changes, should be reported as1000 *1.6855 =168.55dem..