Bob is taking his son to look at colleges. The first college they plan to visit is 150 miles from their home. In the first hour they drive at a rate of 60 mph. If they want to reach their destination in 2.5 hours, what speed must they average for the remainder of their trip? (I wouldn't mind if you use a proportion since that's how I'm supposed to solve it)

Accepted Solution

Answer:[tex]60\ mph[/tex]Step-by-step explanation:we know thatThe speed is equal to divide the distance by the timeLets ----> the speed in mphd ----> the distance in milest ----> the time in seconds[tex]s=\frac{d}{t}[/tex]step 1In the first hour they drive at a rate of 60 mphFind the distance traveledwe have[tex]s=60\ mph[/tex][tex]t=1\ h[/tex]substitute[tex]60=\frac{d}{1}[/tex][tex]d=60\ mi[/tex]soThe remainder of the trip is equal to[tex]150\ mi-60\ mi=90\ mi[/tex]step 2 Find out the average speed for the remainder of the tripwe have[tex]d=90\ mi\\t=2.5-1=1.5\ h[/tex]substitute the values[tex]s=\frac{90}{1.5}=60\ mph[/tex]