Problem Solving (PS) | When they work alone, B needs 25% more time to finish a job than A

When they work alone, B needs 25% more time to finish a job than A does. They two finish the job in 13 days in the following manner: A works alone till half the job is done, then A and B work together for four days, and finally B works alone to complete the remaining 5% of the job. In how many days can B alone finish the entire job?
(A)20
(B)16
(C)22
(D)18
(E) 24

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