A and B can separately do a piece of work in 6 days and 12 days respectively. How long will they together take to do the work ?
A8 days
B6 days
C5 days
D4 days
Answer:
D. 4 days
Read Explanation:
total work = lcm(6, 12) = 12
efficiency of A = 12/6 = 2
efficiency of B = 12/12 = 1
Time taken by both of them to do the work
= total work/ total efficiency
= 12/(2 + 1)
= 4 days