Necesito que hagan el procedimiento y el resultado D:

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?

The length of a rectangle plus its width is 24 cm. the area is 143 square cm. what are the length and width of the rectangle?

The table showed price paid per concert ticket on a popular online auction site. what was the average price paid per ticket