Can someone help ASAP with this worksheet.

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?

B. two events are dependent if the occurrence of one event changes to occurrence of the second event. true or false

What is 10+10+20 about the origin the square root of a triangle.