Can someone help me with this math homework please!

Steve is scuba diving near his home in maui. at one point he is 100 feet below the surface. represent this number with a negative number. if he descends another 5 feet, what negative number will represents his.

Tamera puts 15/4 gallons of gasoline in her car. which mixed number represents the gallons of gasoline? a) 2 3/4 gallons b) 3 1/4 gallons c) 3 3/4 gallons d) 4 1/2 gallons answer it's worth a lot of points!

Olga used 100 ounces of flour to make 225 muffins. how many ounces of flour will be used to make 300 muffins?