Question 147094
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?
.
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)