It takes 4 hours for Party A and Party C to translate together 12 hours, and the rest will be translated by Party B alone. "
That is, A+B works for 4 hours, C+B works for 4 hours, and B 4 hours is completed!
Party B's four-hour work completion:1-4× (110+112) = 4/15.
∴ The efficiency of B is115, so it takes15 hours for B!