Nicole drove six miles to Megan's house at thirty-seven mph. She then drove seventeen miles to Sarah's house. For the entire trip, Nicole averaged a speed of 43 231/905 mph. What was her average speed driving from Megan's to Sarah's house?

Respuesta :

speed = distance / time . . . . . . . . easy to remember: speed is usually miles/hour

43 231/905 = (6 +17)/((6/37 +t) . . . . t is the travel time from Megan's to Sarah's
6/37 +t = 23/(43 231/905) = 905/1702
t = 905/1702 -6/37 = 17/46

The average speed for the trip from Megan's to Sarah's was (17 mi)/(17/46 h) = 46 mi/h.