A can complete a task in 18 days while B can complete the same task in 12 days. If both work together for 6 days, and then A leaves. In how many days will B complete the task?
Answer & explanation
Correct answer: option 3
A = 18 days, B = 12 days,

⇒ A + B worked for 6 days = (2 + 3) x 6 = 5 x 6 = 30 units, ..(Efficiency × Days = Total work)
⇒ Remaining work = 36 - 30 = 6 units,
⇒ Time required for B to complete the work alone = \(\frac{6}{3}\) = 2 days, ..(\(\frac{Work}{Efficiency}\) = Time)