X alone can complete a piece of work in 16 days, while Y alone can complete the same work in 24 days. They work on alternate days starting with Y. In how many days will 50% of the total work be completed?
Answer & explanation
Correct answer: option 2
X = 16 days, Y = 24 days,
⇒ They work on alternate days, starting with Y,
1st day = 2 units,
2nd day = 3 units,
Every 2 days = 5 units of work is done,
So, in 8 days, 20 units of work will be completed,
And in 9 days, 22 units will be completed,
Therefore, in \( { 9}_{3 }^{2 } \) = \(\frac{29}{3}\) days, 50% of the work will be completed.