Given below are two quantities named A and B. Based on the given information, you have to determine the relationship between the two quantities. You should use the given data and your knowledge of Mathematics to choose between the possible answers.

Quantity A: A does one-third as much work as B in one-fifth of the time. If together they take 9 days to complete a work. How much time shall B take to do it alone?  

Quantity B: 20 days