let w = weatbound train speed and e=eastbound train speed
we know that w = e - 16 after three hours the westb train has covered a distance of 3(e -16) miles
the eastb train has covered 3e distance the total of the distance covered by the trains is 480 miles
so it will be 3(e - 16) + 3e = 480 ->> 3e-48+3e = 480 ->> 6e-48=480 dividing by 6 both sides we get
e-8=80 that is e=88 mph and w=88-16=72 mph
so e = 80 mph and w = 72 mph west bound rate = 72 mph