A and B can complete a work in 24 days together. If A alone can complete the work in 36 days, how long will B take to complete the work alone?

Answer: A. 48 days
If A takes 36 days, then B's rate can be calculated as 1/24 - 1/36 = 1/72. Therefore, B will take 72 days to complete the work alone.
Posted in:  Time & Work -  Aptitude -  Mathematics