Final answer:
To calculate the number of extra flowers ordered, subtract the base cost of the standard arrangement from the total cost, and then divide the difference by the price per additional flower. The customer ordered 17 extra flowers.
Step-by-step explanation:
The customer wants to know how many extra flowers they ordered from Fancy Flowers if the total amount paid was $45.40, with each additional flower costing $1.20 after the initial $25 charge for the standard seasonal arrangement. First, we subtract the cost of the standard arrangement from the total amount paid to find out how much was spent on additional flowers: $45.40 - $25 = $20.40. Next, we divide the amount spent on extra flowers by the cost per flower to determine the number of flowers: $20.40 / $1.20 = 17 extra flowers. Therefore, the customer ordered 17 additional flowers.