A driver sets out on a journey. For the first half of the distance she drives at the leisurely pace of 30 mi/h; she drives the second half at 60 mi/h. What is her average speed on this trip?

I know that it will take twice as long to drive the same distance at 30 mi/hr than at 60 mi/hr. The hint my professor gave us said that we should set distance for x but I don't know what to do with that information.

Question

A driver sets out on a journey. For the first half of the distance she drives at the leisurely pace of 30 mi/h; she drives the second half at 60 mi/h. What is her average speed on this trip?



I know that it will take twice as long to drive the same distance at 30 mi/hr than at 60 mi/hr. The hint my professor gave us said that we should set distance for x but I don't know what to do with that information.

anonymous · Answer

That's actual the average of the two speeds. The question is asking for the average speed of the trip.