Библиотеку привезли 560 новых книг причем 25% составляют учебники сколько учебников привезли в библиотеку

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.