X did a task for 24 days and left it incomplete. He could have finished the task all by himself in a total of 36 days. Y, who can finish the task alone in 18 days, will take how many more days to complete the task?

6

X = 36 days, Y = 18 days, 

⇒ A worked for 24 days alone = 1 x 24 = 24 units,  ..(Efficiency × Days = Total work)

⇒ Remaining work = 36 - 24 = 12 units,

⇒ Time required by B to complete the remaining work = \(\frac{12}{2}\) = 6 days    ..(\(\frac{Work}{Efficiency}\) = Time)