a   b
      c
d   e   f   g
  h       i
j   k   l   m
      n
    o   p

1. Place the numbers 1 to 16 in the 16 locations on the eight-pointed star, such that each of the eight lines of numbers has the same sum and the sum of the eight points of the star has the same sum as the lines. Or prove it can't be done.

2. Without the condition that the sum of the points equal that of the lines, find a solution such that each of the eight lines has a common sum. Can solutions for different common sums be found?