How can you decide which operations to use to solve a two-step equation

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?

Which of the following equations is equivalent to x/3-6/x=1

Jo divides a candy bar into eight equal pieces for her children to share she gives three pieces to sam three pieces to leslie and two pieces to margie rose the two month old baby does it doesn't get any what fraction shows how muchw candy each of the four children got. what's the answer to my question