Karan, Arjun and Krunal alone can complete a work in 40,

Solution

Let the total work = 240 units (LCM of 40, 60 and 48) Amount of work done by Karan alone in one day = 240/40 = 6 units Amount of work done by Arjun alone in one day = 240/60 = 4 units Amount of work done by Krunal alone in one day = 240/48 = 5 units Amount of work done by Karan, Arjun and Krunal together in 3 days = 3 × (6 + 4 + 5) = 45 units Amount of work done by Arjun and Krunal together in 5 days = 5 × (4 + 5) = 45 units Remaining work = 240 – 45 – 45 = 150 units So, the time taken by Krunal alone to complete 60 units work = 150/5 = 30 days So, Krunal worked for 30 + 5 + 3 = 38 days