Question: Which of these are partitions of the set of real numbers?
a) the negative real numbers, {0}, the positive real numbers
b) the set of irrational numbers, the set of rational numbers
c) the set of intervals [k, k + 1], k = ..., -2, -1, 0, 1, 2,...
d) the set of intervals (k, k + 1), k = ..., -2, -1, 0, 1, 2,...
e) the set of intervals (k, k + 1], k = ..., -2, -1, 0, 1, 2,...
f) the sets {x + n | n ∈ Z} for all x ∈ [0, 1)