Question

Two buses leave a station at the same time and travel in opposite directions. One bus travels 9 mi faster than the other. If the two buses are 702 mi apart after 6 hours, what is the rate of each bus?

Answer 1

51.75 mph slower bus?
60.75 faster bus?

How would someone go a decimal of a speed?

Answer 2

Distance each bus travels is given as d=tr where
- d is distance bus travels
- t is a time bus travels
- r is a speed of the bus
:
Distance first bus travels for 4 hours is d1=6r.
Distance other bus travels for 4 hours is d2=6(r+9).
:


Total distance between them is 702 miles and since they go in opposite directions this distance is sum of distances each bus travels.
:
d1+d2=702
6r+6(r+9)=702
6r+6r+54=702
12r+54=702
12r=702-54
12r=648
r=648/12
r=54 mi, this is a speed of the first bus
:
r+9=63 mi, this is a speed of the second bus

Answer 3

I was adding instead of subtracting I think.. Here is what I did

6 hrs 9 (slower)
6 hrs +9 mph (faster) = 81
6 hrs both went 702 mi

6s + 6s + 81 = 702
12s = 702
12s= 702 - 81 = 621
12s = 621
12/621 = 51.75 mph (slower)

51.75+ 9mph = 60.75 mph faster