First step is assigning variables. Let's assign P as the number of people in the club. Then looking at the information given, we have:
5/6 * P = 30
If you divide the sides by 5/6, which is the same as multiplying by 6/5, we get:
P = 6/5 * 30 = 36
I hope this helped, I tried to help but this is all I knew.