EMERGENCY! Please give me the correct answer!

There were 816 people at a concert when a band started to play. after each song, only half the people stayed to hear the next song. how many people were left at the concert after x songs? write a function to represent this scenario.

Timmy uses 1 1 2 cups of sugar for every 2 gallons of lemonade he makes. how many cups of sugar would timmy use if he makes 13 gallons of lemonade?

The paint recipe also calls for 1/4 cup of food coloring. tyler says mrs.mcglashan will also need 6 cups of food coloring. do u agree or disagree? explain.