Jackie living room is 20 feet long and 14 feet wide . she wants to put carpet everywhere expect for a section by the door that measure 2 feet and 3 feet. how many square feet of carpet jackie need

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?