Help meh just 1 question 1 pic included...

The blue segment below is a diameter of o. what is the length of the radius of the circle?

Mrs. chibas is making chocolate chip cookies for her daughter's class. she bought a tub of chocolate chip cookie dough that contained 57.6 ounces of dough. if each cookie needs 1.2 ounces of dough, how many cookies can she make

Renting a room at the willow tree resort costs $125 for 2 people. each additional person is $25. write an expression that shows the cost for n extra people