Ravi, Manish and Naveen alone can complete a work in 30 days, 15 days and 10 days respectively. They start the work together but Ravi leaves the work after 2 days of the starting of the work and Manish leaves the work after 3 days more. In how many days Naveen will complete the remaining work?

Let the total work be 30 units (LCM of 30, 15 and 10)
Efficiency of Ravi = 30/30 = 1 unit per day
Efficiency of Manish = 30/15 = 2 units per day
Efficiency of Naveen = 30/10 = 3 units per day
They worked together for 2 days.
Work done in 2 days = 6*2 = 12 units
Remaining work = 18 units
Manish and Naveen worked for 3 days.
Work done in 3 days = 5*3 = 15 units
Remaining work = 3 units.
3 units will be completed by Naveen in 1 day.