Cory decided he wanted to go to the amusement park. The amusement park charges $15.00 for entry and $2.00 per ride Write an equation that model the total cost y that Cory would spend depending on the number of rides the rides.

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?