Answer:
$2.80
Explanation:
We are asked to find the selling price of one gallon milk for which the store pays $2.00 and mark up is 40%.
We know that selling price of an item equals cost of item plus mark up.
The selling price of each gallon of milk would be $2.00 plus 40% of $2.00.
![\text{Selling price of each gallon of milk}=\$2.00+(40)/(100)* \$2.00](https://img.qammunity.org/2020/formulas/mathematics/middle-school/d81ytsv482behgtr0bu4a488d186r8bfe4.png)
![\text{Selling price of each gallon of milk}=\$2.00+0.40* \$2.00](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ia1tsehap7xhm0srsxx2epno6zdbbtmc57.png)
![\text{Selling price of each gallon of milk}=\$2.00+\$0.80](https://img.qammunity.org/2020/formulas/mathematics/middle-school/cmg4reeh7u3xoqoifmw9265wfaliqz8hid.png)
![\text{Selling price of each gallon of milk}=\$2.80](https://img.qammunity.org/2020/formulas/mathematics/middle-school/56gcfanbh41f2dqnzv5c1cc89ooyywayl6.png)
Therefore, the selling price of each gallon of milk is $2.80.