A train head south for Wichita left the station at the same time a train head north for Des Moines left the same station. The train headed to Wichita traveled at 55 miles per hour. The train headed to Des Morines traveled at 70 miles per hour. How many miles apart are the trains ate the end of 3 hours?

A 210 miles
B 156 miles
C 125 miles
D 375 miles

Each train covers a certain distance that is determined by its speed multiplied by the time of travel. Because they began at the same time and travelled for the same amount of time, we simply multiply each train's speed by the time to get how far each train has travelled.

The train headed to Wichita covered a distance of: [tex]$55 \text{ mph} \times 3 \text{ hours} = 165 \text{ miles} $[/tex]

The train headed to Des Moines covers a distance of [tex]$70 \text{ mph} \times 3 \text{ hours} = 210 \text{ miles} $[/tex]

Because the trains are traveling in opposite directions, we add their individual distances to find the total distance between them after 3 hours. So, the trains are:

[tex]$165 \text{ miles} + 210 \text{ miles} = 375 \text{ miles} $[/tex] apart

Therefore, Option D is correct