One copy machine can make 30 copies a minute, and a second…

One copy machine can make 30 copies a minute, and a second copy machine makes 15 copies a minute. If the two copiers work together, how long would it take them to make 900 copies?

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 #43333