5/8：15
=1/8∶3
=1∶24
=1/24
0.8:3/4
=4/5∶3/4
=16/20∶15/20
=16∶15
=16/15
150公顷：3/5平方千米
=0.01∶0.6
=1∶60
=1/60
4吨：750千克
=4∶0.75
=4∶3/4
=16/4∶3/4
=16∶3
=16/3