Two numbers together add to 300. One number is twice the size of the other. What are the two numbers? A. 25; 50 B. 50; 100 C. 75; 150 D. 100; 200 Solution D. Set this up as an equation. A number plus 2 times that number is 300. x + 2x = 300 Solve for x. 3x=300 X=100 So one number is 100 and the other is twice that, or 200..