Question

Sophie drove 225 mi south through the Smoky Mountains. Snow during her return trip made her average speed on the return trip 30 mph slower. The total driving time was 8 hr. Find Sophie’s average sped on each part of the trip.

Answer 1

@Nnesha

Answer 2

let x = speed on her first part of the trip

x-30 is the speed on the second part of her trip coming back

Answer 3

d = r*t
225 = x*t
t = 225/x is the time it takes to drive 225 mi at x mph


d = r*t
225 = (x-30)*t
t = 225/(x-30) is the time it takes to drive 225 mi at x-30 mph

combine the two times and set that equal to 8

\[\Large \frac{225}{x}+\frac{225}{x-30} = 8\]

now solve for x