A works twice as fast as B. If B can complete a work in 12 days independently, the number of days in which A and B can together finish the work in :
Select the correct option:
A) 8
B) 9
C) 4
D) 18
E) None
Ratio of rates of working of A and B = 2 : 1   So, ratio of times taken = 1 : 2   B's 1 day's work = 1/12   Therefore A's 1 day's work = 1/6   (A + B)'s 1 day's work =	(1/6	+ 1/12)= 1/4   So, A and B together can finish the work in 4 days.   Answer: 4
<result>C</result>
A works twice as fast as B. If B can complete a work in 12 days independently, the number of days in which A and B can together finish the work in :