please answer this word problem

[barbie]

Two trains leave the station at the same time, one heading east and the other west. The eastbound train travels at
105
miles per hour. The westbound train travels at
85
miles per hour. How long will it take for the two trains to be
494
miles apart?

 

[math_celebrity]

Time 1, distance apart is 105 + 85 = 190

So every hour, the distance between them is 190 * t where t is the number of hours. Set up our distance function:

D(t) = 190t

We want D(t) = 494
190t = 494

Divide each side by 190
t = 2.6 hours