Answer: Elyse will need 48 cups to mix her fruit drink.
Step-by-step explanation: Elyse can use the unit rate. First she can multiply 4 cups by 4 quarts to find that there are 16 cups in one gallon. She can then multiply 3 gallons by 16 cups to determine that she will need 48 cups of water to mix the fruit drink.
explanation
4 cups * 4 quarts = 16 cups in one gallon
16 cups * 3 gallons = 48 cups required to mix the fruit drink