Walking 7/6 of his usual rate, a boy reaches his school 4…

Walking 7/6 of his usual rate, a boy reaches his school 4 min early. Find his usual time to reach the school?

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 #3360