Ben is farther from his home. You can find out by comparing, from where they are at, during a certain hour.
For example, at 2 hours, Sally had drove 55 miles.
And at 2 hours on the graph, Ben seems to be at 125 miles.
So Ben drove faster than Sally during the first 2 hours.
You just have to keep comparing their miles at a certain hour.
Another example:
At 5 hours, Sally had driven 100 miles. And on the graph, Ben had driven 250 miles after 5 hours of driving. (You can tell because of the line touching the other line at the 250 mark)
