SOLUTION:
Step 1 :
In the question, we are told that:
Johann has traveled 15 miles from his station on the train.
He will continue on the train at 80 miles per hour.
If he ends up traveling a total of 615 miles,
we are meant to find how much longer did it take him.
Step 2:
Let t represents the time, so that we have the following:
![15\text{ + 80t = 615}](https://img.qammunity.org/2023/formulas/mathematics/college/t0hd5hwmazzabkzk8tlkf0bxc5bn37lzu0.png)
Solving this, we have that:
![\begin{gathered} 80t\text{ = 615 - 15} \\ 80\text{ t = 600} \\ \text{Divide both sides by 80, we have that:} \\ t\text{ = }(600)/(80) \\ \text{ t}=\text{ 7. 5 hours} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/mmvfemcf35zp68if6wiec6teiupibytvjk.png)
CONCLUSION:
The final answer is 7. 5 hours