Karan, Arjun and Krunal alone can complete a work in 30, 45 and 36 days respectively. All of them started working together but after 3 days from start Karan left the job and after 5 more days Arjun also left the job. So for how many days did Krunal work?

Solution

Let the total work = 180 units (LCM of 30, 45 and 36) Amount of work done by Karan alone in one day = 180/30 = 6 units Amount of work done by Arjun alone in one day = 180/45 = 4 units Amount of work done by Krunal alone in one day = 180/36 = 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 = 180 – 45 – 45 = 90 units So, the time taken by Krunal alone to complete 90 units work = 90/5 = 18 days So, Krunal worked for 18 + 5 + 3 = 26 days