Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Task No. | Day announced | Options | Viewers' selection | Result |
| --- | --- | --- | --- | --- |
| 1.0 | Day 43 (May 4, 2008) | Alex, Ejay, Josef, Nan, and Robi | Josef | Completed |
| 2.0 | Day 44 (May 5, 2008) | Robi, Valerie, Alex | Robi | Failed |
| 3.0 | Day 45 (May 6, 2008) | Ejay, Alex, Nan | Nan | Completed |
| 4.0 | Day 46 (May 7, 2008) | Valerie, Nicole, Alex | Nicole | Completed |
| 5.0 | Day 47 (May 8, 2008) | Beauty, Ejay, Alex | Beauty | Completed |
| 6.0 | Day 50 (May 11, 2008) | Alex, Ejay, Nan, Robi | Robi | Failed |
| 7.0 | Day 51 (May 12, 2008) | Priscilla, Valerie, Alex, Ejay | Ejay | Failed |
| 8.0 | Day 52 (May 13, 2008) | Rona, Priscilla, Valerie, Alex | Alex | Completed |
| 9.0 | Day 54 (May 15, 2008) | Priscilla, Rona, Valerie | Rona | Completed |
| 10.0 | Day 55 (May 16, 2008) | Valerie, Priscilla | Valerie | Failed |
Question:
when was it announced that the viewers selected robi out of alex, ejay, nan, robi?
Answer:
Day 50 (May 11, 2008)