1/3+3/4+2/5+5/7+9/20+10/21+11/24+19/35
=1/3+3/4+2/5+5/7+1/4+1/5+1/3+1/7+1/3+1/8+19/35
=1/3+1/3+1/3+3/4+1/4+2/5+1/5+5/7+1/7+1/8+19/35
=1+1+3/5+6/7+1/8+19/35
=2+21/35+30/35+19/35+1/8
=2+70/35+1/8
=4+1/8
=33/8