A can do a piece of work in 4 hours; 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?	Options:
A) 11 hours  B) 16 hours  C) 12 hours  D) 13 hours  E) 17 hours
A's 1 hour's work =1/4;   (B + C)'s 1 hour's work = 1/3;   (A + C)'s 1 hour's work = 1/2.   (A + B + C)'s 1 hour's work = ( 1/4 + 1/3 )	= 7/12.   B's 1 hour's work = ( 7/12 - 1/2 ) = 1/12.   Therefore B alone will take 12 hours to do the work.   12 hoursORRE12 hoursT OPTION : "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, while A and C together can do it in 2 hours. How long will B alone take to do it?