Ramu rides his bike at an average speed of 45 km/hr and…

Ramu rides his bike at an average speed of 45 km/hr and reaches his desitination in four hours. Somu covers the same distance in five hours. If Ramu covered his journey at an average speed which was 9 km/hr less and Somu covered his journey at an average speed which was 10 km/hr more, then the difference in their times taken to reach the destination would be (in minutes).

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #29022