amy and her family were traveling during their vacation. she looked at her watch at point 1 in the diagram below, and then again at point 2 in the diagram below. her mom told her how far they traveled in that time as noted below
so if in 2 hours you drove 80 miles the in 1 hour you have to have driven 40 miles (80m/2h) so you have to divide the 1200 miles by the 40mph to find out how many hours the trip will take (1200m/40mph=30h)
