What sort math is this called and how do you work it out

At a lunchron, guests are offered a selection of five different grilled vegetables and four different meats. in how many waya could one choose three vegetables and two meats?

Which equations represents circles that have a diameter of 12 units and a center that lies on the y-axis? check all that apply

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.