A and B, B and C & C and A can finish a piece of work in 12 days, 15 days and 20 days respectively. Working together in how many days will they finish 60% of the work?

06

Total Efficiency of (A + B + B + C + C + A) = 12 w/d

Total efficiency of A + B + C = 6 w/d

60% of the work = 60 × 60% = 36

(A + B + C) will finish it in = \(\frac{36}{6}\) = 6 days