Question 4
Fill the 3 × 3 board with the numbers 1 to 9 so that every row sum and every column sum is prime. The numbers 1, 2 and 4 are fixed as shown. Find the product of the numbers in the four shaded squares.
Clarification for this practice version: the printed single-answer question admits more than one listed product. Select all listed products that are possible; keep all the original conditions.
Clarification for this practice version: the printed single-answer question admits more than one listed product. Select all listed products that are possible; keep all the original conditions.