How much time will it take Jenny to bike 15 miles if she bikes at a speed of 6 mph?

2.5 hours

Step-by-step explanation:

First, try rewriting Jenny's speed in it's fraction form: 6 mi/hr

Next, use the units to set up an equation that relates Jenny's speed to the distance they want to travel. Let's call the unknown time t:

6mi/hr=15mi/t

1/t=6/15 (mi/hr•1/mi)

t=15/6 (hrs/mi•mi)= 15/6 (hrs•mi/mi)= 15/6 hrs

t=2.5hrs

So it'd take Jenny 2.5hrs at 6mph to go 15 miles. The key here is to keep track of the units. You can treat them like fractions and reduce them away as if they were numbers or variables.