Dominic drove from Phoenix to Tucson on Interstate 10, a distance of 116 miles. The speed limit on this highway varies between 55 and 75 miles per hour. He started his trip at 11:44 pm and arrived in Tucson at 1:12 am. Prove that Dominic was speeding at some point during his trip.

How do I do this problem? Would the speed limits and time be points of a line or something like that?

Question

Dominic drove from Phoenix to Tucson on Interstate 10, a distance of 116 miles. The speed limit on this highway varies between 55 and 75 miles per hour. He started his trip at 11:44 pm and arrived in Tucson at 1:12 am. Prove that Dominic was speeding at some point during his trip. 

How do I do this problem? Would the speed limits and time be points of a line or something like that?

joannablackwelder · Answer

Average speed = total distance/total time. Looks like to me that his average speed exceeded the max speed limit.