Are all mixed economies the same?why or why not?

The simple interest in a loan of $200 at 10 percent interest per year is

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?

Which of the following events could increase the demand for labor? a. an increase in the marginal productivity of workers b. a decrease in the amount of capital available for workers to use c. a decrease in the wage paid to workers d. a decrease in output price