David's mom wants to calculate how much it will cost to drive from Los Angeles, CA, to San Francisco, CA. Gas costs $4.00 a gallon, and the gas mileage of their car is 38 miles/gallon. What additional information does David's mom need to do this calculation? the size of the gas tank the distance between the two cities the number of times that the gas tank will be filled along the way the speed limit on the highway between the two towns