Renu can do a piece of work in 6 days, but with the help of her friend Suma , she can do it in 3 days. In what time Suma can do it alone?  Choose the correct choice from the following options:  A) 6  B) 12  C) 14  D) 15  E) 17

Rationale: "renu â € ™ s one day â € ™ s work = 1 / 6 suma â € ™ s one day â € ™ s work = 1 / 3 - 1 / 6 = 1 / 6 suma can do it alone in 6 days . answer : a"
Answer: A