Seeing spots
If you take a domino set and discard all those dominoes which involve a 5 or a 6, leaving 15 dominoes with a 0, 1, 2, 3 or 4 at each end, then the rest can be laid out, spotty sides up, to form a 5-by-6 rectangle. Then, taking the number of spots in each square as that square’s value, the product of each row can be calculated by multiplying together the values of the six squares in that row.
Your task is to lay out the dominoes so that the five products are all different, less than…
