Matrices X, Y and Z have orders 4×3, 3×2 and 2×6 respectively.
(i) Determine the order of the product XYZ.
(ii) Calculate the total number of elements in each of the matrices XY, YZ and XYZ.
(iii) Find the ratio of the number of elements in XY to that in XYZ.
(iv) If all the entries of XY are replaced by their negatives, does the order of the matrix change? State the reason briefly.