Answer: He saved 20 miles.
Explanation:
Given: Mr. Thomas drove from Banesville to Tempe and back.
Distance from Banesville to Tempe = 40 miles
Distance covered in entire journey (Banesville to Tempe and back) = 40+40= 80 miles
But if he go through Georgetown, then
Distance from Banesville to Tempe = 30+20 = 50 miles
Distance covered in entire journey (Banesville to Tempe and back) = 50+50 = 100 miles
Distance he saved = 100 miles - 80 miles = 20 miles
hence, he saved 20 miles.