P alone can complete a job in 7 days. The work done by Q alone in one day is equal to one-sixth of the work done by P alone in one day. In how many days can the work be completed if P and Q work together? Answers:
A) 2 B) 3 C) 4 D) 5 E) 6
P's rate is 1/7   Q's rate is 1/42   The combined rate is 1/7 + 1/42 = 1/6   If they work together, the job will take 6 days.   The answer is 6.
<result>E</result>
P alone can complete a job in 7 days. The work done by Q alone in one day is equal to one-sixth of the work done by P alone in one day. In how many days can the work be completed if P and Q work together?