Tony buys 4kg of £1.60 per kilogram and 2kg of onions at £1.80 she pays with a £20 note. how much change does she receive?

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.