Sue Flay has a debt per customer of $8 and a profit per customer of $0.33. Cassa Role has a debt per customer of $3 and a profit per customer of $0.33.
To answer the first question, we can calculate Sue Flay's debt and profit per customer. After 500 customers, Sue was $4000 in debt, which means her debt per customer is $4000/500 = $8.
After 3000 customers, she was $1000 ahead, which means her profit per customer is $1000/3000 = $0.33.
To answer the second question, we can calculate Cassa Role's debt and profit per customer. After 2000 customers, Cassa Role still owed $6000 to the bank, which means her debt per customer is $6000/2000 = $3.
After 4500 customers, she was ahead by $1500, which means her profit per customer is $1500/4500 = $0.33.