@Lindastanich,
The single digit factors of 24 involving odd numbers are 1x3x8, 2x3x4, 1x6x4
Of these, 1,3,8 and 2,3,4 add to a multiple of 3
So the possible solutions are all
odd combinations of either bunch,
i.e. those not ending in an even number,
e.g 831, 423, etc...
And 15 squared =225, so chose all combinations above that.
(Since this only excludes one combination, it seems rather a poor question!)