Who took over as the new chairman of the Tata Sons owned Vistara Airline in 2016? Prior to this, he was the Managing Director of Titan for a long time.
A, B and C can complete a work in 20, 24 and 30 days respectively. All three of them starts together but after 4 days A leaves the job and B left the job 6days before the work was completed. C completed the remaining work alone. In how many days was the total work completed?