As seen above, you can arrange the digits 1-9 in a 3-by-3 grid so that the number formed in the first row can be multplied by 2 to form the number in the second row and by 3 to form the third row.
It can be done a few different ways using a few different number combinations, but what is the one solution with a 5 placed in the centre square? Enter just the numbers found in each row in order, with a space between each. For example, the answer for the first grid shown above would be 219 438 657.