1. Lesson 4-8 Rate-time- Distance Problems
D = rt
D=distance r= speed t= time

2. 1. At noon a private plane left Austin for Los Angeles, 2100 Km away, flying at 500 km/h. One hour later a jet left Los Angeles for Austin at 700 km/h. At what time did they pass each other?

3. Rate
time
Distance
Plane
500 t
500t
Jet
700 t
700(t-1)
2100

4. 500t (t – 1)=2100
500t t – 700= 2100
+700=+700
1200t = 1400
t= 1h and 20 minute
At noon = 13 and 20 minute
Or 1:20 P.M

5. At 8:00 A. M. the Smiths left a campground, driving at 48 mi/h
At 8:00 A.M. the Smiths left a campground, driving at 48 mi/h. At 8:20 A.M the Garcias left the same campground and followed the same route, driving at 60 mi/h. At what time did they overtake the Smiths?

6. Rate
Time
Distance
Smiths
48 mi/h t
48t
Garcias
60 mi/h
T – 1 3
60(t +1)

7. 48 t = 60( t - 1/3)
48t = 60t - 20
12t = t= 50 minute
The Smiths overtake at 8:50