0.1x0.3/0.2x0.4/0.3x0.5/0.4x0.6/0.5x0.7/0.6x0.8/0.7x0.9/0.8=0.1x0.9/0.2=0.45
把除法变成乘法,再约分
1/10÷(2/10÷3/10)÷(3/10÷4/10))÷(4/10÷5/10))÷(5/10÷6/10))÷(6/10÷7/10))÷(7/10÷8/10))÷(8/10÷9/10)=1/10÷(2/10*10/3))÷(3/10*10/4))÷(4/10÷*10/5))÷(5/10*10/6))÷(6/10*10/7))÷7/10*10/8)))÷(8/10÷10/9)=1/10*3/2*3/4*5/4*5/6*7/6*8/7*9/8=9/20