Anuj, Bittu, and Chintu can individually complete a certain task in 84 days, 105 days, and 60 days, respectively. They all begin working together, but Bittu leaves after working for 12 days. Determine the total number of days required to complete the entire task.

ATQ, Let total work = 420 days (LCM of 84, 105 and 60) Amount of work completed by Anuj in one day = 420/84 = 5 units Amount of work completed by Bittu in one day = 420/105 = 4 units Amount of work completed by Chintu in one day = 420/60 = 7 units Amount of work completed by Anuj, Bittu and Chintu together in 12 days = 12 × (5 + 4 + 7) = 192 units Amount of time taken by Anuj and Chintu together to complete the remaining work = (420 – 192)/12 = 19 days Desired time = 12 + 19 = 31 days