A carpenter worked alone for 1 day on a job that would take him 4 more days to finish. He and another carpenter completed the job in 2 more days. How many days would it have taken the second carpenter to do the complete job working alone? Choose the correct answer
A) 5  B) 7  C) 9  D) 14  E) 24

Rationale: "a carpenter worked only 1 day on something that takes him 4 more days . means ; carpenter finishes his work in 5 days . let his buddy finish the same task in x days . respective rates per day : 1 / 5 and 1 / x to complete 1 work : first guy worked for 3 days @ rate = 1 / 5 per day . second one worked for 2 days @ rate = 1 / x per day expression : days * rate = work 3 * 1 / 5 + 2 * 1 / x = 1 3 x + 10 = 5 x 2 x = 10 x = 5 days . ans : a"
Answer: A