Blast from the Past 11. Carpet is being installed in a bedroom. The bedroom has a perimeter of 52 feet and a width of 12 feet. What is the total number of square feet of carpet needed for the bedroom?​

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?