Answer:
[tex]60\ mph[/tex]
Step-by-step explanation:
we know that
The speed is equal to divide the distance by the time
Let
s ----> the speed in mph
d ----> the distance in miles
t ----> the time in seconds
[tex]s=\frac{d}{t}[/tex]
step 1
In the first hour they drive at a rate of 60 mph
Find the distance traveled
we have
[tex]s=60\ mph[/tex]
[tex]t=1\ h[/tex]
substitute
[tex]60=\frac{d}{1}[/tex]
[tex]d=60\ mi[/tex]
so
The 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 trip
we 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]