Launs

$\ln { x } =\quad \ln { 1 } +\ln { 2 } +\ln { 3 } \dots \dots +\ln { y }$

$\implies \ln { x\quad -\quad \ln { y } } =\quad \ln { \{ 1\times 2\times 3\times 4.......\times (y-1) } \}$

$\implies \ln { \dfrac { x }{ y } } =\quad \ln { \{ (y-1)!\} }$

$\implies \dfrac{x}{y} = (y-1)! = 720 = 6!$

$y-1 = 6,~ \therefore y=7$

$\& \because \dfrac{x}{y} = 720~, ~\therefore ~x = 720\times y = 5040$

$\therefore x+y = 5040 + 7= 5047$

x/y =6! Thus y=7 (next of 6) x=7*720=5040 x+y= 5047