A and B working separately can complete a piece of work in 9 and 12 days respectively. If they work alternatively starting from A in how many days will the work be completed?  Choose the correct choice: A) 10.21 days B) 10.23 days C) 18.25 days D) 10.25 days E) 40.25 days
Explanation:   A takes 9 days to complete a piece of work. B takes 12 days to complete a piece of work.   =&gt; In one day A came complete 1/9th of the task(x/9)   =&gt; In one day B can complete 1/12th of the job.(x/12)   First day x/9th work will be done next day x/12th and so on:   Together A and B can do x/9 + x/12 work.   =&gt;(x/9) + (x/12) = 7/36th work done   In 10 days 35/36th of the work will be done.   On 11th day it will be A’s chance. It takes A 1 day to complete 1/9th work.   So, 1/36th work will be done in 1/4 days.   =&gt;10.25 days   ANSWER: 10.25 days
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A and B working separately can complete a piece of work in 9 and 12 days respectively. If they work alternatively starting from A in how many days will the work be completed?