Machine A takes 50 hours to complete a certain job and starts…

Machine A takes 50 hours to complete a certain job and starts that job at 6AM. After four hour of working alone, machine A is joined by machine B and together they complete the job at 1PM. How long would it have taken machine B to complete the job if it had worked alone for the entire job?

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 #19005