Look at positions (i), (ii) and (iii) of a die. How many of the dice (a) to (d) can be positions of the same die?

From the views the pairs are 1–3, 2–5 and 4–6. All four candidates avoid opposite pairs, so the order round the corner decides. (a) is (i) turned so that 4 is on top, and (c) is (iii) turned so that 5 is on top: both fit. (b) and (d) list the same faces in the reverse order, so they are mirror images. Two dice fit.