Question Number 114288 by mathdave last updated on 18/Sep/20
Commented by bemath last updated on 18/Sep/20
$$\mathrm{56}{xyz}\:=\:\mathrm{3}! \\ $$$$\mathrm{6}{wxyz}\:=\:\mathrm{4}! \\ $$$$\mathrm{7}{qrstu}\:=\mathrm{4}! \\ $$$$\mathrm{8}{abcd}\:=\:\mathrm{4}! \\ $$$$\Sigma\:{number}\:=\:\mathrm{6}+\mathrm{3}×\mathrm{24}\:=\mathrm{78} \\ $$