A and B can do a piece of work in 8 days. B and C can do it in 12 days and A and C in 16 days. Working together they will complete the work in how many days?
Options:  A) 5.38 days  B) 9.38 days  C) 7.38 days  D) 3.38 days  E) 9.38 days
7.38 days   7.38 days   A + B = 1/8   B + 7.38 days = 1/12   7.38 days + A = 1/16   -------------------------------   2(A + B +7.38 days) = 1/8 + 1/12 + 1/16 = 13/48   A + B +7.38 days = 13/96   96/13 = 7.38 days
<result>C</result>
A and B can do a piece of work in 8 days. B and C can do it in 12 days and A and C in 16 days. Working together they will complete the work in how many days?