a/(b*c)=0.0...012 /(0.0...025*0.0...08)=1.2*10^(-100)/[2.5*10^(-100)*8*10^(-100)]=1.2/[2.5*8*10^(-100)]=1.2/[20*10^(-100)]=1.2/[2*10^(-99)]=(1.2/2)*10^99=0.6*10^99=6*10^98a/(b*c)=6后面有98个0a=0.0...012,中间有199个0哟a/(b*c)=0.0...012 /(0.0...025*0.0...08)=1.2*10^(-199)/[2.5*10^(-100)*8*10^(-100)]=12*10^(-200)/[2.5*10^(-100)*8*10^(-100)]=12/(2.5*8)=12/20=3/4