Undisciplined

OneOneSeven

And yes, 6 and 7 are one of the 3 possible answer sets. Good job!

south_korea_ln

> edit: how to not spoil the puzzle for others?

I suggested a feature for this yesterday: https://github.com/stackernews/stacker.news/issues/1422

10! = 10×9×8×7×6×5×4×3×2×1
= 5×2×3×3×2×2×2×7×3×2×5×2×2×3×2×1
= 7×5×5×3×3×3×3×2×2×2×2×2×2×2×2×1
So either m or n must be >= 7
= 7!×5×3×3×2×2×2×2×1
= 7! ×6×5×4×3×2×1
= 7!×6!
m=7, n=6
m×n=42

edit: how to not spoil the puzzle for others?

charts_and_numbers

[Daily puzzle] If m! x n! = 10! then m x n = ?

10! = 10×9×8×7×6×5×4×3×2×1
= 5×2×3×3×2×2×2×7×3×2×5×2×2×3×2×1
= 7×5×5×3×3×3×3×2×2×2×2×2×2×2×2×1
So either m or n must be >= 7 
= 7!×5×3×3×2×2×2×2×1
= 7! ×6×5×4×3×2×1
= 7!×6!
m=7, n=6
m×n=42

edit: how to not spoil the puzzle for others?