Help please Two trains travel for eleven hours starting from

Help please! Two trains travel for eleven hours, starting from the same place traveling in opposite directions. One train travels at an average rate that is 15 miles per hour faster than the other train. Find the rate of each train if they are 291 miles apart after three hours.

Solution

You will need to apply the distance formula:
d = rt
where
d is distance
r is rate or speed
t is time
.
Let x = speed of one train
then
x+15 = speed of second train
.
3(x) + 3(x+15) = 291
3x + 3x + 165 = 291
6x + 165 = 291
6x = 126
x = 21 mph
.
second train:
x+15 = 21+15 = 36 mph
.
The speeds of the two trains are 21 and 36 mph.