Fesdus goes out cycling outdoors

Fesdus goes out cycling outdoors. He travels at an average speed of 3km/h, to the top of the hill where the midpoint of the trip is. Going down hill, Juan travels at an average speed of 9km/h. Which of the following is the closest approximation of Fesdus's average speed, in kilometers per hour, for the round trip?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #71986