A non-scale model of the earth has a diameter of 18 in. Within an outer clay layer, there is a core made of a ball with a diameter of 3 in. What is the volume of the clay?

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?