A and B can do a piece of work in 2 days, B and C in 3 days, C and A in 4 days. How long will C take to do it?  Choose the correct choice
A) 14 days B) 20 days C) 22 days D) 24 days E) 26 days

Rationale: "2 c = 1 / 3 + 1 / 4 – 1 / 2 = 1 / 12 c = 1 / 24 = > 24 days answer : d"
Answer: D