Can anyone solve this

Which type of graph would allow us to quickly see how many students between 100 and 200 students were treated?

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?

Which statement best describes how to determine whether f(x) = x squared- x +8 is an even function ?