Using the given equation, it is found that the train will travel 15 miles in 50 seconds.
[tex]D(T) = 0.3T[/tex]
In this problem, we want to find the distance traveled by the train after 50 seconds, hence, [tex]T = 50[/tex], and:
[tex]D(50) = 0.3(50) = 15[/tex]
The train will travel 15 miles in 50 seconds.
A similar problem, also involving the numeric value of an equation, is given at https://brainly.com/question/25537936