1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+3/5+4/5+……+1/10+2/10+3/10+……+8/10+9/10
=1/2+2/2+3/2+4/2+5/2+6/2+7/2+8/2+9/2
=45/2
=22又1/2
=22.5
1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+3/5+4/5+……+1/10+2/10+3/10+……+8/10+9/10
=1/2+2/2+3/2+4/2+5/2+6/2+7/2+8/2+9/2
=45/2
=22又1/2
=22.5