A can do a piece of work in 4 hours; B and C together can do it in 3 hours, which A and C together can do it in 2 hours. How long will B alone take to do it?
Select the correct option: A) 15 hours B) 14 hours C) 12 hours D) 74 hours E) 79 hours
A's 1 hour work = 1/4;   (B + C)'s 1 hour work = 1/3;   (A + C)'s 1 hour work = 1/2   (A + B + C)'s 1 hour work = (1/4 + 1/3) = 7/12   B's 1 hour work = (7/12 + 1/2) = 1/12   B alone will take 12 hours to do the work.   Answer:12 hours
<result>C</result>
A can do a piece of work in 4 hours; B and C together can do it in 3 hours, which A and C together can do it in 2 hours. How long will B alone take to do it?