Question

Let U = {q, r, s, t, u, v, w, x, y, z}
A = {q, s, u, w, y}
B = {q, s, y, z}
C = {v, w, x, y, z}.

Determine whether the set is well defined. The set of rivers that flow south to north

A. well defined

B. not well defined

Answer 1

i think not well defind

Answer 2

its not specific