If they get $11,000, and you know they spent about at least $4,000 to rent the club, then subtract 4,000 from 11,000 to get 7,000. Then you know that it cost about $20 per student for food etc, so then divide 7,000 by 20 to get how many students. The answer is 350. To check, say 350 x $20 to see how much it cost for all of them. You get 7,000. Then add 4,000 to 7,000 to get a total of how much it all cost, 11,000. This confirms that 350 student could attend if they raised up to $11,000. I hope this makes sense and helps :)
