These are equivalent to using using a deck of 4 cards to emulate a 6-sided die.
A. Assign integer values to a, b, c, d
so that the 6 possible
pairwise sums
a+b, a+c, a+d,
b+c, b+d, c+d
are 1, 2, 3, 4, 5, 6
though not necessarily in that order.
B. Same as above but with noninteger values for a, b, c, d .
C. Assign integer values from the range 0 through 6
to a, b, c, d so that
the 6 possible pairwise absolute
differences |a-b|, |a-c|, |a-d|,
|b-c|, |b-d|, |c-d|
are 1, 2, 3, 4, 5, 6
though not necessarily in that order.
Two solutions.