First, we will calculate the total cost of the gas needed for a tank.
The cost of gasoline is $2.56 per gallon, and you need 15 gallons.
Total cost of a tank of gas = Cost per gallon × Number of gallons Total cost = $2.56 × 15 = $38.40
Since you and your friend are splitting the cost, each person will pay half of the total cost.
Amount each pays = Total cost / 2 Amount each pays = $38.40 / 2 = $19.20
Therefore, each of you will pay $19.20.