Probability a point is chosen in a circle(shaded region) surrounded by a square in which the circle has a radius of 2?

Out of the 150 students at a summer camp, 72 signed up for canoeing. there were 23 students who signed up for trekking, and 13 of those students also signed up for canoeing. use a two-way table to organize the information and answer the following question: approximately what percentage of students signed up for neither canoeing nor trekking?