200-50= 150 So you need to get 150 dollars in a month. If you get 20 dollars a week, then 150/20 will give you 7.5. So it will take you 7.5 weeks to get 150 dollars
There are now 28 members all you do is 80 times 0.65 = 52 but you still have to subtract 80 - 52 to find the number of members left SOOOO 28 members still there 52 members quit