Melody is placing sushi rolls on plates. She has 72 California Sushi Rolls and 60 Spicy Tuna Sushi Rolls. She wants to include both appetizers on each plate. Each plate must have the same number of California Sushi Rolls and the same number of Spicy Tuna Sushi Rolls. What is the greatest number of plates she can make using all of the sushi rolls? Type your answer...

Step 1 ：The problem is asking for the greatest common divisor (GCD) of the number of California Sushi Rolls and Spicy Tuna Sushi Rolls. The GCD is the largest number that divides both numbers without leaving a remainder. This is because each plate must have the same number of each type of sushi roll, and we want to use all the sushi rolls.

Step 2 ：Let's denote the number of California Sushi Rolls as \(a = 72\) and the number of Spicy Tuna Sushi Rolls as \(b = 60\).

Step 3 ：We need to find the greatest common divisor (GCD) of \(a\) and \(b\).

Step 4 ：The greatest common divisor (GCD) of \(a\) and \(b\) is 12.

Step 5 ：So, the greatest number of plates Melody can make using all of the sushi rolls is \(\boxed{12}\).