Working together, A, B and C can finish a piece of work in 3 hours. A finishes the same work in 8 hours and B finishes it in 6 hours. How long will it take for C alone to finish the same work?
P, Q and R together can do a piece of work in 56 days. P and Q together can do one-fourth as much work as R alone. In how many days can P and Q together complete the entire work?