The following input-output pairs have been observed during the operation of a time-invariant system: x1(n) = {1,0, 2} t. yi (n) = {0, 1, 2} x2(n) = {0, 0, 3} y2 (n) = (0, 1,0, 2} x3(n) = {0,0, 0, 1}