A and B can do a piece of work in 30 day and 40 days, respectively. They began the work together but after a certain time. A leaves off and B completed the remaining work in 25 days. After how many days did A leave?

STAFF SELECTION COMMISSION Multi Tasking (Non-Technical) Staff SOLVED PAPER (14th September 2023: Shift 1) SSC MTS Shift 1 Numerical Aptitude  Question 42 :  A and B can do a piece of work in 30 day and 40 days, respectively. The…