How much less, in dollars, was the total cost of Andrew's order compared to the sum of the total costs for Matthew's 2 orders?

This choice underestimates the difference between Andrew's and Matthew's total costs. If Andrew's order is compared to the costs of both orders placed by Matthew, the calculations yield a more significant disparity, showing that $20 does not accurately reflect the actual difference.

Selecting $35 also fails to capture the true difference. The calculations indicate that it was insufficient to represent the total costs for both orders combined, as they exceed this amount, making $35 an incorrect option.

This option is still lower than the actual difference determined from the order calculations. The total difference calculated shows that $45 does not encompass the full extent of the cost disparity between Andrew's and Matthew's orders.

While $55 is a significant amount, it still does not represent the complete difference between the total costs of both orders. The calculations reveal that the true difference is higher, making $55 an incorrect choice as well.