Let us assume the number of hamburgers sold = x
Then
The total number of cheeseburgers sold = x + 66
Total number of hamburgers and cheeseburgers sold = 566
So
x + x + 66 = 566
2x + 66 = 566
2x = 566 - 66
2x = 500
x = 500/2
= 250
From the above deduction, it can be easily concluded that the total number of hamburgers sold was 250. I hope that the procedure is clear enough for you to understand.
