20 POINTS! NEED THIS DONE ASAP

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?

Luke wants to reduce the area of his rectangular garden by 1/4 the expression 14/w can be used to represent this change. what is another way to write this expression?

Sammie has 3 times as many goldfish as nora. nora has 4 goldfish. how many goldfish do sammie and nora have in all?