(0.35*5.1*81)除以(0.17*8.1*0.4)
=(3.5*1.7*3*8.1)/(0.17*8.1*0.4)
=(3.5*0.17*30*8.1)/(0.17*8.1*0.4)
=105/0.4
=1050/4
=525/2