Help I be trying so but can figure out the answer

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?

Simplify. 3(4+4x) (type your answer in with no spaces)

The police chief wants to know if the city’s african americans feel that the police are doing a good job. identify the management problem (i. e dependent variable) and identify the independent variable.