On a certain Monday, Carlos drove to work at an average speed…

On a certain Monday, Carlos drove to work at an average speed of 20 miles per hour and home from work along exactly the same route at an average speed of 40 miles per hour. Which of the following is closest to his average speed for both trips combined?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #33226