Well, for slices, that might be 3000. But I don't know if you mean for kids or adults, so for adults I would have to say 6000 or maybe 6500.
It depends how many slices each person wanted.
E.G 3 slices each = 390 slices
How many pizza's that it will take to feed 60 people will vary depending on how hungry people are and the size of the pizza. If you use a large pizza with 10 slices and figure everyone will eat at least 2 slices, you will need about 12 to 20 pizza's.
6 Slices = 2-3 pax
A sheet pizza will feed 6 to 8 with 24 slices in a sheet usually up to 32 slices best to figure 24 at 4 slices a person
A large Domino's Pizza is about 14 inches in diameter and is typically cut into eight slices. It can be expected to feed about 3-5 adults, on average.
A large pizza typically contains 8 slices and will typically feed 3-4 people. Sides are also available including cheese sticks, wings, chicken poppers and chocolate chip cookies.
there are 10 slices in a large Pizza
there are 8 slices
3 to 4
There are 24 square slices
I believe that there are 8 slices
About 67,200 slices
I think you should do some math. Assume every person will eat up to 2 pieces, so that is 350 slices of pizza. Typical Pizza is sliced up in 8 pieces so divide 350 slices by 8 = 43.75 round up 44 pizza's total. Now for toppings that is entirely up to you. :)