What is the first step that shows an error in the solution to the equation

How do you solve a question like this?

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

Set up and solve a proportion for the following application problem. if 55 pounds of grass seed cover 404 square feet, how many pounds are needed for 7272 square feet?