A shirt cost $45 it is on sale at 40% what is the discount? HELP

Plz which expression is equivalent to the expression below?

Ahome improvement store rents it’s delivery truck for $19 for the first 75 minutes and $4.75 for each additional 1/4 hour. if a customer rented the truck at 11: 10 am and returned the truck at 1: 40 pm the same day, what would his rental cost be?

Prove that 16^4-2^13-4^5 is divisible by 11.