John completes a piece of work in 8 days, Rose completes the same work in 16 days. If both of them work together, then the number of days required to complete the work is?
Choose the correct answer:
A) 6 days
B) 5.33 days
C) 10 days
D) 12 days
E) 14 days

Rationale: if a can complete a work in x days and b can complete the same work in y days , then , both of them together can complete the work in x y / x + y days . that is , the required no . of days = 8 × 16 / 24 = 5.33 days answer : b
Answer: B