-165 degrees find the exact value of sine, cosine, and tangent

In a singing competition, there are 150 participants. at the end of each round, 40% of the participants are eliminated. how many participants are left after n rounds?

Pls the last one and it has to be like number 6

I'm a polygon i have no parallel lines i am formed 3 line segments i have one right angle two of my angles are angles what am i