hard algebra problem help?
I train of length 100 meters drives at a relatively slow speed. A runner starts behind the train and runs past the train to the front, and then returns the same route behind the train. The speed of the runner is 3 times the speed of the train. What distance has the train travelled in this period?
Comments
Let the speed of train be x meters / minute
THEN the speed of runner is 3x meters/ minute
Time taken by runner to reach the front = 100 /2x minutes
Time taken by runner to reach the back = 100/ 4x minutes
Total time = 50/x + 25/x = 75/x minutes
Distance covered by train = x * 75 /x = 75 meters ANSWER
A train of length 100 meters drives at a relatively slow speed.
A runner starts behind the train and runs past the train to the front,
and then returns the same route behind the train.
The speed of the runner is 3 times the speed of the train.
What distance has the train travelled in this period?
Let x be the distance the train travelled in this period.
The runner runs at 3 times the speed of the train.
Speed x time = distance