What is the greatest common factor of 21, 27, and 39?

Which statements are true? see picture

What is the equation of the graph below? y=sec(x)-4

Zoey made 5 1/2 cups of trail mix for a camping trip. she wants to divide the trail mix into 3/4 cup servings. a. ten people are going on the trip. can zoey make enough 3/4 cup servings so that each person gets one serving? b. what size would the servings need to be for everyone to have a serving?