I don’t think you can delete questions
Answer:

And we know that the level is decreasing 20% each day so then we can use the following model for the problem

Where t represent the number of days and L the level for this case we want to fnd the level after two days so then t =2 and replacing we got:

Step-by-step explanation:
For this case we know that the initial volume of water is:

And we know that the level is decreasing 20% each day so then we can use the following model for the problem

Where t represent the number of days and L the level for this case we want to fnd the level after two days so then t =2 and replacing we got:

The passenger train is going 120MPH and the freight train is traveling 40MPH
Unless if you have the solution for a you can find b