Divide the yin-yang symbol (shown below) with a straight line\par
that divides both the black region and the white region into regions\par
with equal areas.
In a square oil field, a drilling rig is 21000 feet from one
corner of the field, 18000 feet from the opposite corner of the field, and
6000 feet from a third corner. How far is the rig from the remaining corner?
In the diagram below, enter numbers into the squares so that the
number appearing in the square labeled 0 gives the total number of 0's you
entered in the diagram, the number appearing in the square labeled 1 gives
the total number of 1's you entered in the diagram, etc.
A hexahedron is a polyhedron with six faces. A cube is one
example of a hexahedron and a pentagonal pyramid is another. How many
essentially different hexahedra are there? (Two polyhedra are
essentially different if one can be deformed into the other. For
example a cube and a truncated square pyramid are essentially the same,but a
pentagonal pyramid and a cube are not.)