Ashok can complete a work in 10 days if he works for 4 hours everyday. Bharath can complete the same work in 4 days and Charan in 8 days but have to work 8 hours and 7 hours a day respectively. If Bharath and Charan can complete another work in 7 days working for 4 hours a day, then how many days would Ashok take to complete the work if he works for 5 hours a day?