Question 974055
 Nancy drove 1 hour longer than Deborah at an average speed 4 kilometers
per hour faster than Deborah.
:
 Edward drove 3 hours longer than Deborah at an average speed 12 kilometers per hour faster than Deborah.
:
 If Nancy drove 80 kilometers more than Deborah, then how many more kilometers did Edward drive than Deborah?
:
Assign 60km/hr as Deb's speed
let t = Deb's travel time
then
60t = Deb's distance
:
64 = Nan's speed
(t+1) = Nan's time
then
64(t+1) = Nan's dist

:
72 = Ed's speed
(t+3) = Ed's time
then
72(t+3)= Ed's distance
:
If Nancy drove 80 kilometers more than Deborah, 
Nan's dist = Deb's dist + 80 km 
64(t+1) = 60t + 80
6tt + 64 = 60t + 80
64t - 60t = 80 - 64
4t = 16
t = 4 hrs is Deb's travel time
then
5 hrs is Nan's travel time
and
7 hrs is Ed's travel time
:
Find the distance each has traveled
4 * 60 = 240 Km
5 * 64 = 320 Km
7 * 72 = 504 km
"how many more kilometers did Edward drive than Deborah?"
504 - 240 = 264 km further