Two trains leave the same station at the same time, but are headed in opposite directions. One train travels at 70 mph and the other train travels at 80 mph.

Question

How much times passes until the trains are 600 mi apart?

Answer 1

let the time be x
Then the first train will go 70x mi
other train will go 80x mi
As the are passing through opposite direction.
then
70x+80x = 600
or, x = 4