Ratio and fees

Question

Members pay six dollars membership fee and three dollars for each aerobic class nonmembers pay five dollars for each aerobic class what number will the cost members and nonmembers be the same

Answer 1

Let's call N, the number which the cost will be equal. So,

 

6+3N=5N

Hence: N=3. 

Sanity check: 6+3*3=5*3=15