A and B can do a piece of work in 4 days, B and C in 6 days, C and A in 3 days. How long will C take to do it? Choose the correct option.
A) 8 days  B) 10 days  C) 12 days  D) 4 days  E) 12 days

Rationale: "2 c = 1 / 6 + 1 / 3 – 1 / 4 = 1 / 4 c = 1 / 8 = > 8 days answer : a"
Answer: A