A can do a work in 6days. B can do in 12days. If both A&B are working together in how many days they can finish the work? Answers.
A) 4 B) 5 C) 6 D) 10 E) 15

Rationale: 1 day work of a = 1 / 6 1 day work of b = 1 / 12 1 day work of a & b = 1 / 6 + 1 / 12 = 1 / 4 a & b finish the work in 4 days answer is a
Answer: A