X, Y, Z working alone finish constructing a house in 4, 6…

X, Y, Z working alone finish constructing a house in 4, 6 and 12 hrs. resp. X starts alone and works for 1 hr. He is then joined by Y and they work together for 1 hr. Finally Z joins them and they all work together to finish the work. If they start working at 9 am, at what time will they finish?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #48777