Problema Solution
two trains left the same station at the same time. Train A traveled north at 28 mph and train B traveled south at 52 mph. How much time passed before they were 320 miles apart?
Answer provided by our tutors
Let ' t' be the time that we are looking for.
We know that the speed is equal to the distance divided by time.
The distance equals to speed multiplied by time.
Now we have:
Train A has speed of 28 mph and after t time will pass: S1 = 28 * t miles
Train B has speed of 52 mph and after t time will pass: S2 = 52 * t miles
Since A is going north and B is going to the south (opposite directions) the distance between the trains will be:
S1 + S2 = 320
28 * t + 52 * t =320
80 * t = 320
t = 320 / 80
t= 4 hours
Indeed
After 4 hours the train A will pass 28*4 = 112 miles
After 4 hours the train b will pass 52*4 = 208 miles
Or the total distance between the trains after 4 hours will be: 112 + 208 = 320.
After 4 hours the trains will be 320 miles apart.