1)x:40=8:5
5x=40*8
5x=320
x=64
2)1/5:2/5=x:3/4
2/5x=1/5*3/4
2/5x=3/20
x=3/8
3)1.5:x=2.4:3.6
2.4x=3.6*1.5
2.4x=5.4
x=2.25