Substitute to Find the Value of the Expression $\frac { 2140 } { t }$

Substitute to find the value of the expression.
-A train must cover a distance of 2140 miles. The velocity, in miles per hour, of the train is $\frac { 2140 } { t }$ where $t$ is the time, in hours, to complete the trip. If the train completes the trip in 20 hours, what is its velocity?

A) $102 \mathrm { mph }$
B) $0.01 \mathrm { mph }$
C) $107 \mathrm { mph }$
D) $42,800 \mathrm { mph }$