Yesterday it took Robert 6 hours to drive from City A to…

Yesterday it took Robert 6 hours to drive from City A to City B. Today it took Robert 4.5 hours to drive back from City В to City A along the same route. If he had saved 30 minutes in both trips, the speed for the round trip would be 90 miles per hour. What is the distance between city A and city B?

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 #10544