Question

Two cars raced at a race track. the faster car traveled 20 mph faster than the slower car. in the time that the slower car traveled 165 miles, the faster car traveled 225 miles. if the speeds of the cars remained constant, how fast did the slower car travel during the race? distance (mi) rate (mph) time (h) slower car 165 r startfraction 165 over r endfraction faster car 225 r 20 startfraction 225 over r 20 endfraction 55 mph 60 mph 75 mph 130 mph

1. thienhuong
If the faster car is travelling 20 mph faster then slower car then the speed of slower car is 55mph and faster car is 75 mph.
Given that the faster car is travelling 20 mph faster than slower car and when slower car travels 165 miles the faster car travels 225 miles.
We are required to find the speed of slower car and faster car.
let the speed of slower car be x mph.
In this way the speed of faster car be (x+20) mph.
Speed=Distance/ time
We have to first take slower car.
x=165/Time
Time=165/x———–1
Now by taking faster car.
x+20=225/time
Time=225/(x+20)——-2
From equation 1 an equation 2.
165/x=225/(x+20)
225x=165x+3300
225x-165x=3300
60x=3300
x=55 mph
Faster car=55+20
=75 mph.
Hence if the faster car is travelling 20 mph faster then slower car then the speed of slower car is 55mph and faster car is 75 mph.