Kim was reviewing the water bills of a dog daycare. She determined that its highest and lowest bills of $3600 and $2800 were incurred in the months of May and November, respectively. If 500 dogs were washed in May and 200 dogs were washed in November, using the high / low method. What was the variable cost per dog associated with the company's water bill?

Simon, aged 10, is invited to a classmate's birthday party at an exclusive ski resort on march 15th. the day will include 4 hours of snowboarding, lunch and birthday cake. simon's mother checks a box on the invitation that says "yes, we will attend" and returns it to the classmate's address. unfortunately, they later don't attend the party when simon comes down with the flu. on march 17th, simon's mother receives an invoice in the mail from simon's classmate for $35 that says, "party no-show fee." can simon's classmate collect the fee?