Brian and Jake left their homes which are 500 miles apart an

Brian and Jake left their homes, which are 500 miles apart, and drove straight toward each other. It took 4 hours for the two to meet. If Jake\'s speed was 15 mph slower than Brian\'s speed, what was Brian\'s speed?

Solution

Use D = RT
where
D = distance
R = rate (mph)
T = time (hours)
.
Let x = Brian\'s speed
then
x-3 = Jake\'s speed
.
The idea is that the combined \"distance\" traveled by Brian and Jake should be 500 miles.
distance Brian traveled = RT = 4x
distance Jake traveled = RT = 4(x-3)
.
\"distance Brian traveled\" + \"distance Jake traveled\" = 500
4x + 4(x-3) = 500
4x + 4x - 12 = 500
8x = 512
x = 64 mph (Brian\'s speed)
x-3 = 64-3 = 61 mph (Jake\'s speed)