If you are using a 2" deep cake pan you would need 13.5 cups of batter.
It depends on how deep the cake pan is.
I would use two and a half, but since that's not possible, I would get two and have extra batter. Mind you, no matter what batter, a cake/brownie must be 3/4 of the way full. hope this helped:)
4 boxes for a single pan
Most cake mixes are for a 9x13 pan which is 117 sq. inches. 12x12 is 144 sq. inches. 1 mix would be enough and shorten the cooking time by 5 to 8 minutes.
about 1 and a half
1/2 way filled
1/2 full
It depends on how deep the cake pan is.
Your batter would overflow.
15 cups of batter. bake at 325 degrees for 75-85 minutes. Use a baking core.
I would use two and a half, but since that's not possible, I would get two and have extra batter. Mind you, no matter what batter, a cake/brownie must be 3/4 of the way full. hope this helped:)
4 boxes for a single pan
Just fill each pan a little over halfway full so it will have plenty of room to rise
Preferably not, the tins that you use should have an added overall area of 81'' square (presuming your nine inch tins are square). Therefore the ten inch pan (if square) will be too big. Though if you don't mind a slightly thinner cake then it would be okay.
144 1-inch squares. 36 2-inch squares.
You should order for only 90% of your guests. Some people will not eat the cake. So again, only order for 90% - in your case that means 12 people or one cake box mix - or one 9 inch round/square cake.
you should make your stand 3 ft. otherwise, make it 4.