Please answer the questions below with workings!! (4,5 &6)

Which function has the smallest y-intercept value

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?

Does the point (1, sqrt 7) lie on circle shown.