if borrows 1cad in canada and s**es in us,the company will gain 1cad*(spot rate)*(1+interest rate in us)/(1 year forward rate)after 1 year,which ** 1*0,9*(1+3%)/0.8=1.15875cad.the principal and interest to be repayed will be 1cad*(1+interest rate in canada),which ** 1*(1+4%)=1.04cad.after repaying the 1.04cad,the company will still h**e a positive profit of 1.15875-1.04=0.11875cad.thus we can make an arbitrage profit.