Zam leaves home everyday at 4 p.m to pick his son from…

Zam leaves home everyday at 4 p.m to pick his son from school and returns home at 6 p.m. One day, the school was over at 4 p.m and the son started walking home from school. Zam, unaware of this, starts from home as usual and meets his son on the way and returns home with him 15 minutes early. If the speed of Zam is 30 km\hr, find the speed of his son.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #12440