On a certain hot day, a gas of tank in a truck experiences a volume expansion along with the gasoline inside the tank. We would like to determine how much of the gasoline will overflow during this expansion, assuming that the tank was initially filled to the brim with gasoline. We have to basically use the volume expansion equation to calculate the volume expansion for both the steel tank and the gasoline. To calculate how much actually overflows, we just take the difference between the two quantities.