What’s the answer pre algebra

With this question! what is process of elimination? ? p.s. my brothers acc got banned so add his new one @ yamauchiyamyam17

Awater tank holds 18000 gallons. how long will it take for the water level to reach 6000 gallons if the water is used at anaverage rate of 450 gallons per day

Reinel saves 30% of every pay check. his paycheck last week was 560$. how much did reniel save last week?