A and B can complete a piece of work in 30 days. B and C in 10 days and C and A in 5 days. If all of them work together, the time taken in completing the work is:
Answer & explanation
Correct answer: option 3
$2A + 2B + 2C = 10$ unit
$2(A+ B + C) =\frac{10}{2}= 5$ unit in one day
Total work = 30
So work will be finished in = $\frac{30}{5}= 6$ days