David is president of the student council. when the leadership team met for the for the first time he asked each person to shake everyone else's hand. if there were six people at the meeting, how many handshakes were made.

Solve the problem by using a venn diagram a group of students were surveyed about their taste in music. they were asked how they like three types of music: rock, country western and jazz. the results are summarized below: no one dislikes all three types of music. six like all three types of music. eleven don’t like country western. sixteen like jazz. three like country western and jazz, but not rock. six don’t like rock. eight like rock and country western. seven don’t like jazz. how many students were surveyed?

The area of each triangle is 7 square units. the surface area of the triangular prism is

The roof of a farm silo is the shape of a hemisphere and is made of sheet tin. if the diameter of the silo is 126.5 feet, how much sheet tin is needed to make the roof? (use π = 3.1416.)