A can do a work in 6 days. B can do the same work in 12 days. If both A & B are working together in how many days they will finish the work?	Choose the correct choice from the following:
A) 3	B) 5	C) 4	D) 2	E) 6
A rate = 1/6   B rate = 1/12   (A+B) rate = (1/6)+(1/12) = 1/4   A &amp; B finish the work in 4days   correct option is 4
<result>C</result>
A can do a work in 6 days. B can do the same work in 12 days. If both A & B are working together in how many days they will finish the work?