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 ?
"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 e ."
divide(const_1, add(divide(const_1, 7), divide(divide(const_1, 7), const_3)))