Car 1 travels from point A to point B.. Car 2 leaves 2 hours later, but goes 10 miles an hour faster and passes car 1 in 11 hours.. How fast does each car go??
Make this chart
Distance Rate Time
Car 1
Car 2
Let x = the rate of Car 1
Car 2...goes 10 miles an hour faster
So the rate of Car 2 = x+10
Fill those rates in:
Distance Rate Time
Car 1 x
Car 2 x+10
Car 2...passes car 1 in 11 hours
So fill in 11 for Car 2's time:
Distance Rate Time
Car 1 x
Car 2 x+10 11
Car 2 leaves 2 hours later
This means Car 1 traveled 2 hours longer than Car 2,
so Car 1's time is 11+2 = 13. Fill that in for
Car 1's time.
Distance Rate Time
Car 1 x 13
Car 2 x+10 11
Now we use the formula
to fill
in the distances:
Distance Rate Time
Car 1 13x x 13
Car 2 11(x+10) x+10 11
Now the distances traveled by each car are the same,
so we set the two distances equal:
13x = 11(x+10)
Solve that equation for x and get x = 55 mph for Car 1.
Car 2 went 10 mph faster, so it went 65 mph.
Edwin