Abhi takes 40 more time than Ashu to complete a work If Ashu works for X days amp after that the rem...........

Abhi takes 40% more time than Ashu to complete a work. If Ashu works for X days & after that the remaining work is completed by Abhi in (x + 4) days than ratio of work done by Ashu and by Abhi is 7 : 9. Find in how many days Abhi will complete the work alone?