Final answer:
To find the total cost of the muffins you buy, divide the amount you have by the price of each muffin, then multiply the price of each muffin by the number of muffins you can buy. The total cost is $18.
Step-by-step explanation:
To find the total cost of the muffins you buy, you need to multiply the price of each muffin by the number of muffins you buy. The price of each muffin is $2.25. Since you have $20 to spend and you want to buy as many muffins as possible, you divide the total amount you have by the price of each muffin:
$20 / $2.25 = 8.89 (approximately)
Since you can't buy a fraction of a muffin, you can only buy a whole number of muffins. Therefore, you can buy a maximum of 8 muffins. To find the total cost, you multiply the price of each muffin by the number of muffins:
8 x $2.25 = $18
The total cost of the muffins you buy is $18.