（1又99分之5+3又33分之5+9又11分之5）/（1又99分之1+3又33分之1+9又11分之1）
=(104/99+104/33+104/5)/(100/9+100/33+100/11)
=104*(1/99+1/33+1/11)/[100*(1/99+1/33+1/11)]
=104/100
=26/25