Let A = fcard is an Aceg and R = fcard is redg. Are A and R independent? Now, pick two cards out of the deck sequentially without replacement. Are F = frst card is an Aceg and S = fsecond card is an Aceg independent?

What does x = in this equation x+3+2x=x+5

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?

Ireally don't understand this, i'm really an idiot but i want to know how to figure this out. !