A is twice as good a workman as B and they took 5 days together to do the work B alone can do it in? Pick
A) 15 days B) 88 days C) 21 days D) 11 days E) 13 days

Rationale: "wc = 2 : 1 2 x + x = 1 / 5 x = 1 / 15 = > 15 days answer : a"
Answer: A