Answer: 375 hamburgers
Explanation:
Let's assume that x is the number of hamburgers sold on Monday.
According to the problem, the number of cheeseburgers sold is 62 fewer than the number of hamburgers sold. So the number of cheeseburgers sold is x-62.
The total number of hamburgers and cheeseburgers sold is 688. So we can set up an equation:
x + (x-62) = 688
Simplifying this equation, we get:
2x - 62 = 688
Adding 62 to both sides, we get:
2x = 750
Dividing both sides by 2, we get:
x = 375
Therefore, 375 hamburgers were sold on Monday.