Your bank gives you a special loan of $112,000. at the end of 30 years, you will pay the bank $176,400 in simple interest. what is the annual interest rate on your loan? i know the answer but someone tell me how to do it?

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.