(1+1/6)×1/6+1/6
=7/6×1/6+1/6
=7/36+1/6
=13/36
分析：设丙为单位1.
则：乙比丙多1/6
乙=1+1/6
甲比乙多1/6×(1+1/6)=7/36
则：甲比丙多7/36+1/6=13/36