‘A’ is 20% more efficient than ‘B’. ‘A’ and ‘B’ work together for 6 days after which ‘A’ is replaced by ‘C’. ‘B’ and ‘C’ together take 6 more days to finish the work. If ‘A’ alone could’ve finished the whole work in 20 days, then find the time taken by ‘C’ to finish 60% work alone.