A, Band C can do a piece of work in 35 days, 20 days and 55 days respectively, working alone. How soon can the work be done if A is assisted by Band C on alternate days?
Choose one:  A) 7 days  B) 8 days  C) 9 days  D) 10 days  E) 16 days
(A+B)'s 1 day's work = 1/35+1/20 = 11/140   (A+C)'s 1 day's work = 1/35+1/55 = 18/385   work done in 2 day's = 11/140+18/385 = 48/383   48/383th work done in 2 days   work done= 383/48*2 = 16 days (approx)   ANSW16 daysR:16 days
<result>E</result>
A, Band C can do a piece of work in 35 days, 20 days and 55 days respectively, working alone. How soon can the work be done if A is assisted by Band C on alternate days?