Answer: 100 minutes
Step-by-step explanation:
With the given information, we can use a proportion to figure out how long it would take for Jen to bike 30 miles.
[tex]\frac{12mi}{40min} =\frac{30mi}{x} \\[/tex]
[tex]12x=30*40[/tex]
[tex]12x=1200[/tex]
[tex]x=100[/tex]