第二周吃了全部的(1-4/7)*(1/4)=(3/7)*(1/4)=3/28
(7/8)*[ 1-(4/7)-(3/28)-1/8)]
=(7/8)*(11/56)
=11/64(吨)
(7/8-7/8*4/7)*1/4-7/8*1/8
=(7/8-4/8)*1/4-7/64
=3/8*1/4-7/64
=3/32-7/64
=6/64-7/64
=-1/64
(7/8-7/8*4/7)*1/4-7/8*1/8
=(7/8-4/8)*1/4-7/64
=3/8*1/4-7/64
=3/32-7/64
=6/64-7/64
=1/64我觉得是