Selections 2, 3, 5, 6 are polynomials.
1 and 4 are not. The coefficients don't have to be integers, but the powers of the variables need to be positive integers. In 1, you have x^-1. in 4, you have x^(1/2).
If p = 2, insert the value of p.
2^3 = 2 x 2 x 2 = 4 x 2 = 8
so p^3 = 8
In order to find the area, you multiply the width (7), height (6) and length (12). But the problem states that the height has changed from 6 to 6 minus3, which would be 3. So you multiply 3, 7, and 12.
It's a coffin because the person who makes it is alive so they don't need to use it, the person who buys it is also alive and buying it for someone else.
The person who is using it has passed away so they can't see or feel anything.
:( This is one morbid riddle.