The correct answer is 130 miles per hour
Step-by-step explanation:
The speed refers to the rate of movement of a body, based on the distance and time of the movement. Additionally, the general formula to calculate the speed is to divide the distances by the time or s (speed) = d (distance) / t (time). Moreover, this factor is measured in units such as kilometers per hour or miles per hour.
In the case presented, we know the total distance was 390 miles and the total time was 3 hours. The formula and process are shown below.
Speed=
![(d)/(t)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/bc0c5rdr6ecxpvez0s9lguijb4z1rp1bck.png)
Speed =
![(390 miles)/(3 hours)](https://img.qammunity.org/2021/formulas/mathematics/college/gne9d24pl8ney9s4oxw4ts3kv05nql3dq9.png)
Speed= 130 miles per hour
Therefore, the speed of the train in miles per hour is 130