Respuesta :

ImSlightlyConfused
5.40/x=0.75/1

cross multiply:
0.75x=5.40

divide:
0.75x/0.75=5.40/0.75

x=$7.20

just to check:
5.40/3=1.8

1.8*4=7.2

the answer is $7.20 for 1 hour