P alone can complete a piece of work in 6 days. Work done by Q alone in one day is equal to one-third 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? Choices
A) 491/2)
B) 4(1/2)
C) 4(1/8)
D) 7(1/2)
E) 4(5/2)
Work done by P alone in one day = 1/6th of the total work done by Q alone in one day = 1/3(of that done by P in one day) = 1/3(1/6 of the total) = 1/18 of the total.   Work done by P and Q, working together in one day = 1/6 + 1/18 = 4/18 = 2/9 of the total   They would take 9/2 days = 4 (1/2) days to complete the work working together.   Answer:7(1/2)
<result>D</result>
P alone can complete a piece of work in 6 days. Work done by Q alone in one day is equal to one-third 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?