Dn Monday, Josiah had sș gallons of gas in his car. On his way to work,
he added 4 gallons to the tank. He then drove to work and used 1
gallons. Three days later, he added 2- gallons of gas to his tank. He
then used 4 gallons of gas driving to his grandparent's house. How much
gas remains in Josiah's tank?