What is the unit for f(x)?

Plz ! what is the volume of this pyramid? with numbers of 30cm 14cm 18cm

You got a job selling magazines door-to-door. you are paid $100 per day plus $1.50 for each magazine you sell. which recursive formula models this situation?

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?