Sandy left downtown Durham, and three hours later, Mary left going 46 mph faster to catch up. After another two hours, Mary caught up. Find Sandy's average speed.

Accepted Solution

Answer:   30 2/3 mphStep-by-step explanation:Going 46 mph faster for 2 hours, Mary closed a (46 mi/h)×(2 h) = 92 mile gap. That gap was created in 3 hours by Sandy going ...   (92 mi)/(3 h) = 30 2/3 mi/hSandy's average speed was 30 2/3 mph._____Comment on the situationWe wonder what sort of road and traffic situation would allow Mary to go 76 2/3 mph in downtown Durham, while Sandy traversed the same route at 30 2/3 mph.