To do this I'm going to set up an equation. We don't know how many hamburgers were sold so we will call it x. The number of cheeseburgers sold was two times the number of hamburgers sold so we are going to call the number of cheeseburgers 2x. These add up to 267 so we can make and solve the equation:
x+2x=267
3x=267
x=89
89 hamburgers and 178 cheeseburgers were sold.
