A certain lab experiments with white and brown mice only

A certain lab experiments with white and brown mice only. In one experiment, 2/3 of the mice are white. If there are 9 brown mice in the experiment, how many mice in total are in the experiment?

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 #6442