(1)20%=1/5
1/5x=48
x=240
(2)60%=3/5
3/5x-2/5x=4
x=20
(3)七月份:100-5=95(吨)
5÷95x100%=5.26%
(4)设路长x米
1/3x+150=l/2x
x=900