Car A travels 180 miles in the same time it takes Car B to t

Car A travels 180 miles in the same time it takes Car B to travel 120 miles. If one car is going 20 mph faster than the other car, find both speeds?

Solution

st=d
A) (s+20)t=180
B) st=120
.
180/(s+20)=120/s
180s=120(s+20)
180s=120s+2400
3s=2s+40
s=40 mph
s+20=60mph