Answer:
It will take 1 hour and 12 minutes for the two trains to be 192 miles apart
Step-by-step explanation:
The total distance between the two trains is the distance traveled by both trains. The distance traveled by the eastbound train is 85 mph * elapsed time and the distance traveled by the westbound train is 75 * elapsed time.
The combined formula is distance traveled = speed of first train * elapsed time + speed of second train * elapsed time.
Since the elapsed time is equal for both trains then the formula is modified as distance traveled = (speed of first train + speed of second train) * elapsed time.
Solving for the elapsed time
distance traveled = (speed of first train + speed of second train) * elapsed time
192 miles = (85mph + 75 mph) * elapsed time
192 miles = 160 mph * elapsed time
elapsed time = 192 miles / 160 mph
elapsed time = 1.2 hours
elapsed time = 1 hour and 12 minutes
It will take 1 hour and 12 minutes for the two trains to be 192 miles apart.
