A freight train averages 30 miles per hour traveling to its destination
with full cars and 40 miles per hour
on the return trip with empty cars.
Find the total time in terms of d.
Show your work

Consider the following sets.u = {all real number points on a number line)a = {solutions to the inequality 3x + 4 2 13}b = {solutions to the inequality=x+354}for which values of x is a u b = ? 2< x< 325x$3x$ 2 and x2 3x < 2 and x > 3