A can do a piece of work in 4hours. B and C together can do it in 3 hours, while A and C together can do it in 2 hours. How long will B alone take to do it?	Choose the correct choice from the following options:
A) 8 hours
B) 10 hours
C) 12 hours
D) 24 hours
E) 30 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 1hour's work= (7/12-1/2)= 1/12   B alone will take 12 hours to do the work.   correct option is 12 hours
<result>C</result>
A can do a piece of work in 4hours. B and C together can do it in 3 hours, while A and C together can do it in 2 hours. How long will B alone take to do it?