Answer:
0.19 hours
Step-by-step explanation:
we know that
The cost to rent a bike for 4 hours is $21
so
using proportion
Find out how many hours of bike use does a customer get per dollar
Let
x ----> the number of hours
[tex]\frac{21}{4}\ \frac{\$}{h}=\frac{1}{x}\ \frac{\$}{h}\\\\x=4/21\\\\x= 0.19\ hours[/tex]