1/10+1/40+1/88+1/154+1/238+1/340=
问题描述：
1/10+1/40+1/88+1/154+1/238+1/340=
答
1/10+1/40+1/88+1/154+1/238+1/340
=1/3×(3/10+3/40+3/88+3/154+3/238+3/340)
=1/3×(1/2-1/5+1/5-1/8+1/8-1/11+1/11-1/14+1/14-1/17+1/17-1/20)
=1/3×(1/2-1/20)
=1/3×9/20
=3/20