15) In a basketball game, Reggie made 11 field goals (shots). Each of the field goals were worth either 2 or 3 points, and Reggie scored a total of 25 points from field goals. Part A: Let x represent the number of 2-point field goals and y represent the number of 3-point field goals. Write a system of equations in terms of x and y to model the situation.

Part B: Using any method, find how many 2-point and 3-point field goals Reggie made in the game.

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?