Venn diagram of triangles, isosceles triangles, quadrilateral and Polygons

Which type of graph would allow us to quickly see how many students between 100 and 200 students were treated?

What is the greatest number of parts of a circle that can be formed by cutting the circle with 7 straight cuts? (note: the parts do not have to be equal in size)

For the chance to be team captain, the numbers 1-30 are put in a hat and you get two chances to pick a number, without replacement. which formula correctly shows how to find the probability that you choose the number 1 and then 2?