A and B can complete a work in 15 days together. If A alone can do it in 25 days, how long will B ta

A. 30 days

B. 20 days

C. 25 days

D. 15 days

E. None of the above

Answer: A. 30 days

Let B's time be x days. The equation is 1/25 + 1/x = 1/15. Solving gives x = 30 days.

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