A and B can do a piece of work in 16 days, B and C in 24 days, C and A in 12 days. How long will C take to do it? Choose the correct choice from the following answers.
A) 16 days B) 55 days C) 24 days D) 32 days E) 22 days

Rationale: "2 c = 1 / 24 + 1 / 12 – 1 / 16 = 1 / 16 c = 1 / 32 = > 32 days answer : d"
Answer: D