Please help with my Solid Mensuration Problem

Bunker Hill Monument is a stone structure in the form of the frustum of a regular square pyramid whose height is 220ft. and whose base edges are 15ft. and 30ft., respectively. Through the center of the monument is a cylindrical opening 11ft. in diameter at the top and 15ft. in diameter at the bottom. Find the volume of the stone in the monument.

The Answer in the back of the book Solid Mensuration by Kern and Bland is 86,068 cubic feet.
I don't have a diagram for this. Please help i don't know the solution for this

There are important contradictions in your question. I'm not willing to speculate on what you really mean. I suggest you clarify these if you want a serious answer. They are:

1. If the pyramid is square then all 4 sides of the base must be equal - not one of 15 ft and the other of 30 ft.

2. Is the so called "cylindrical" opening vertical?. If it is indeed a cylinder then it must have only one diameter - not 11 ft at the top and 15 ft at the base.

3. Information on the size of the upper horizontal surface (top or roof) is missing. Is that perhaps what you mean by the 15 ft "base" edge?

You'd better start expressing yourself more clearly and consistently if you want to mix it with engineers.

Find the volume of the pyramid and subtract the volume of the hole.
The hole is part of the volume of a cone. There are formulas online for both of these objects.