Timothy leaves home for school, riding his bicycle at a rate of…

Timothy leaves home for school, riding his bicycle at a rate of 9 miles per hour. Fifteen minutes after he leaves, his mother sees Timothy’s math homework lying on his bed and immediately leaves home to bring it to him. If his mother drives at 33 miles per hour, how far (in terms of miles) must she drive before she reaches Timothy? I think is a 700 level problem but I tag it as 600/700, let me know. Either way I hope in an explanationThanks

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 #10067