P is three times as fast as Q and working together, they can complete a work in 12 days. In how many days can Q alone complete the work?	Choose the correct choice from the following options:
A) 11 days
B) 16 days
C) 13 days
D) 15 days
E) 19 days
B   16 days   P = 3Q   P + Q = 3Q + Q = 4Q   These 4Q people can do the work in 12 days, which means Q can do the work in 48 days.   Hence, P can do the work in 16 days.
<result>B</result>
P is three times as fast as Q and working together, they can complete a work in 12 days. In how many days can Q alone complete the work?