Put 9 egg tarts, 3 in each row, and the radius of each egg tart is:
12/3/2=2
Egg tart area: 3.14 * 2 * 2 * 9 = 3.14× 36.
Put 16 egg tarts, 4 in each row, and the radius of egg tarts is:
12/4/2= 1.5
The area of egg tart is 3.14 *1.5 *1.5 *16 = 3.14× 36.
The area of the egg tart is equal, and the blank of the first one is equal to the blank of the second one.
It's 100%