Q:

To do a certain work, the ratio of the efficiencies of X and Y is 5:4. Working together, they can complete the same work in 10 days. Y alone starts the work and leaves after 5 days. The remaining work will be completed by X alone in:

• 1
  14 days
• 2
  12 days
• 3
  10 days
• 4
  15 days