Answer:
315/50
Step-by-step explanation:
trust me bro!
Both trains travel for 7 time units.
Train A travels 385 distance units, so its speed is

Train B travels 577.5 distance units, so its speed is

Note that the units are not specified, but considering that we're talking about trains, the graph is likely to be showing distance in km (or miles) and time in hours.
Also, the distance traveled by train B is not perfectly aligned with the grid, so I assumed that it was the average between the two ticks of 550 and 605.
There isn't a rectangular prism. Guess 12.
You can download the app photo math and that will help you
I believe that answer is 31