Help me please I don’t get it

Is a positive integer raised to a negative power always positive

Ebuka's monthly rent is $750. if ebuka pays the rent late, his landlord charges 4% interest per week that the payment is late. write a function that gives the total cost r(t), in dollars, of ebuka's rent if he pays it t weeks late.

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.