A,B,C can complete a piece of work in 24,6,12 days. Working together, they complete the same work in how many days?	Choose one
A) 2  B) 4 / 5  C) 7 / 9  D) 10  E) 24 / 7

Rationale: "a + b + c 1 day work = 1 / 24 + 1 / 6 + 1 / 12 = 7 / 24 a , b , c together will complete the job in 24 / 7 days answer is e"
Answer: E