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?

24 hours

A + B + C = 3 hrs,

A = 8 hrs,

B = 6 hrs,

⇒ A + B + C = 8  (Efficiency)

⇒ 3 + 4 + C = 8,

⇒ 7 + C = 8,

⇒ C = 1,

⇒ Time required by C to complete total work = \(\frac{24}{1}\) = 24 hrs.   ..(\(\frac{Work}{Efficiency}\) = Time)