What is 0.4 divided by 0.242? Divide I keep getting 0.65. I need help showing step by step

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?

What is the perimeter of a rectangle if the length is 5 and the width is x?

Find the volume of the wedge cut from the first octant by the cylinder z=12-3y^2 and the plane x+y=2.