9分之1×72×8分之1
=(9分之1×8分之1)×72
=72分之1×72
=1
25%×8×40%
=0.25×8×0.4
=(0.25×0.4)×8
=0.1×8
=0.8
157×24%+343×24%
=157×0.24+343×0.24
=(157+343)×0.24
=500×0.24
=120