My acct got deleted and my old acct was monsa123 so can someone pls add me on here

Which one ? is the answer and how to find this answer

What happens to the area as the sliders are adjusted? what do you think the formula for the area of a triangle is divided by 2?

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?