Do it for me! i need both of this questions

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?

One of the complementary angles is 4 degrees mor than the other. find the angles (recall that complementary angles are angles whose sum is 90 degrees.) which of the following can not be used to solve the problem if x represents one of the angles? a. 2x-4=90 b. 2x+4=90 c. x+4=90

Here is another math questions. i will keep asking different questions. 4^2x=6