=1/9+2/9+……+8/9+10/99+11/99+……+89/99
=(1/9+8/9)+(2/9+7/9)+……+(4/9+5/9)+(10/99+89/99)+(11/99+88/99)+……+(49/99+50/99)
=1+1+……+1
=4+40
=44
=1/9+2/9+……+8/9+10/99+11/99+……+89/99
=(1/9+8/9)+(2/9+7/9)+……+(4/9+5/9)+(10/99+89/99)+(11/99+88/99)+……+(49/99+50/99)
=1+1+……+1
=4+40
=44