Every hour, a runner is able to run the same number of miles. If on his 3rd hour of
running he has gone 15 miles, and on his 5th hour of running he has gone 25 miles. If
you graphed hours on the x axis and miles on the y-axis, what would be the slope of
the line representing this run?
a) 10 miles per hour
b) 3 miles per hour
c) 5 miles per hour
d) 1/5 miles per hour