Depends on how big you cut the pieces. If you cut 2x2 inch pieces, a 12x18 cake will yield 54 servings.
80
A 12" x 18" cake pan will make 72 servings.
117
Typically a full sheet cake pan is 18"x24" and will serve 108 2"x2"servings. This size pan, however, will not fit in a standard oven so manufacturers have created other sizes that are still referred to as "full-sheet." Though the math really doesn't work out: 1/4 sheet pans are 9"x13" 1/2 sheet pans are 12"x 18" Full sheet pans are 18"x24"
The serving amount depends on how big the pieces are cut into.
You should get six 4x4 servings with a a 1x9 on the bottom ans a 1x13 on the side left over. So, basically 7 servings.
9 inches x 9 inches = 81 one inch servings
A baking sheet is a sheet pan or a baking tray.
The answer depends on the measurement units used and also on how large the helpings are.
12 to 16 depending on how large you cut them...
Sheetcake pans come in a variety of sizes and depths. What size you want to use depends on the number of servings you want. Also, make sure the pan will fit in your oven. Not all full sheet cake pans fit in all ovens.