A can do a piece of work in 3 hours; B and C together can do it in 2 hours, which A and C together can do it in 2 hours. How long will B alone take to do it?  Choose the most appropriate option.
A) 6hours B) 3hours C) 2hours D) 5hours E) 4hours
A's 1 hour work = 1/3;   (B + C)'s 1 hour work = 1/2;   (A + C)'s 1 hour work = 1/2   (A + B + C)'s 1 hour work = (1/3 + 1/2) = 5/6   B's 1 hour work = (5/6 - 1/2) = 1/3   B alone will take 3 hours to do the work.   Answer:3hours
<result>B</result>
A can do a piece of work in 3 hours; B and C together can do it in 2 hours, which A and C together can do it in 2 hours. How long will B alone take to do it?