A and B can do a work in 12 days, B and C in 30 days and C and A in 36 days. In how many days will the work be completed, if all three of them work together?	Options.
A) 124/13 days.
B) 241/13 days.
C) 180/13 days.
D) 155/13 days.
E) 150/13 days.
C   180/13 days.   One day work of A and B = 1/12   One day work of B and 180/13 days. = 1/30   One day work of 180/13 days. and A = 1/36   2(A + B + 180/13 days.) = 1/12 + 1/30 + 1/36   2(A + B + 180/13 days.) = 13/90   (A + B + 180/13 days.) = 13/180   Number of days required = 180/13 days.
<result>C</result>
A and B can do a work in 12 days, B and C in 30 days and C and A in 36 days. In how many days will the work be completed, if all three of them work together?