Final answer:
David can prepare 8 cups of juice per day, given that he can make 2 gallons of juice in 4 days and 1 gallon is equal to 16 cups.
Step-by-step explanation:
The question asks how many cups of juice David can prepare per day if he can make 2 gallons of juice in 4 days. Since 1 gallon is equivalent to 16 cups, David can prepare a total of 2 gallons * 16 cups/gallon = 32 cups in 4 days. To find out how many cups he can prepare per day, we divide the total cups by the number of days.
32 cups / 4 days = 8 cups/day
Therefore, David can prepare 8 cups of juice each day.