5/8×72%÷3/4
=5/8*18/25*4/3
=9/20*4/3
=3/5
3.6×5/8+6.4×62.5%
=3.6*5/8+6.4*5/8
=(3.6+6.4)*5/8
=10*5/8
=25/4
60×(5/12-40%)
=60*5/12-60*2/5
=25-24
=1
解:设五星商场有职工X人
(1-40%)X+20=(1-20%)X
0.6X+20=0.8X
0.6X=0.8X-20
-0.2X=-20
0.2X=20
X=100
40%X=40
答:五星商场男职工有40名.