X can do a piece of work in 40 days; Y can…

X can do a piece of work in 40 days; Y can do the same in 30 days. X started alone but left the work after 10 days, then Y worked at it for 10 days. Z finished the remaining work in 10 days. Z alone can do the whole work in?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #34489