Plz solve this Bindi Riddle for me

Re: Plz solve this Bindi Riddle for me
I will have to make one presumption; all of them are pretty bright.

The answer is 18.

SOME are wearing red, and SOME are wearing green. It's important, because we know that at least one is green, and at least one is red.

If there was only one green woman, she should know that she is green after the first song because everyone else is red.

If two people had green, then let's look at it from one of the reds perspective. At the beginning of the first song I would know that I am one of the two green ones, or i am looking at the only green one. If that woman goes up to collect the prize after song one, I know that I am red. If the other green woman doesn't go up to collect the prize I know that I am green and can prepare to go up and collect the prize with the other green woman after the second song is finished.

This continues in the same pattern. Since they went up after the 18th song, it means 18 people went up. Or maybe they went up at the beginning of the 18th song, in this case 17 people went up.

This means that there were more people in red, than in green (otherwise people in red would have gone up earlier).
If I was there and I saw that the majority were red, then I would go up after the first song. I wouldn't really know if I was red or green, but I would gladly take the risk based on probability and say that I'm red. So I guess none of them are intelligent enough to get that. There is an upper and lower limit to their intelligence. Or they would never lie.

My understanding of riddles like these is that each participant has an optimum level of reasoning and is also honest.

If there are two dancers with green bindis, at the end of one dance, neither green would move. It's important, though, that they not see that no one else is moving to claim the prize, as they would then immediately know that the person who is wearing green believes someone else is wearing green, and would then move to claim the prize. For the purpose of coming to an optimal and definitive answer, let it be true that regardless of the number of participants, none of them are in a position to observe who may or may not try to claim a prize at the end of a dance and are only made aware of whether a prize has been claimed when notified by the DJ at the beginning of the next song.

That being true, both dancers with green bindis will observe that the other has not claimed a prize after the first song and will then both go to make their claim at the end of the second song.

If there are three dancers wearing green they will each notice at the beginning of the third song that neither of the two dancers wearing green bindis has claimed a prize and know that they too have a green bindi, which leads all three to make a claim after the third song. And so on. Therefore the number of green bindis each dancer is required to see before claiming a prize is equal to the number of songs played--when they are made aware that no one has claimed a prize at the beginning of the next song they will then know that they have a green bindi and move to claim it at the end of the song. In your example, the dancer described knows she has a green bindi at the conclusion of the seventeenth song ("No one came after first song change... none at second change. But when 18th song was played, a lady with [a] green bindi walked to get a prize...")

So there are eighteen dancers who have a green bindi, all of whom claim a prize at the conclusion of the 18th song.

The number of red bindis is irrelevant as in order for a dancer with a red bindi to think they have a green bindi it requires sub-optimal reasoning on the part of the dancers with the green bindi.

For instance, if for whatever reason all of the dancers wearing green bindis neglected to claim a prize at the end of the 18th song, every person wearing a red bindi would also think they have a green bindi.