Joe starts a gym. In the first year, 300 people join. If the membership grows at an annual rate of 4%, how many members will there be after 5 years?

300(0.4)=120

300 on the first year,
(120)(5)=600 more members after 5 years

(300)+(600)=900

there will be 900 members all in all after 5 years.