5) A cross-section of the cube is outlined in the diagram. Which two terms BEST describes the shape of the cross-section? A) square B) rectangle C) acute angles D) right triangle E) equilateral triangle please help

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?