峰 寫到:襪子好像沒有分左右#ed_op#br#ed_cl#[C(6,1)*C(5,2)]/C(12,4)
#ed_op#br#ed_cl#不,沒有分左右,但有兩隻...原來的才對:#ed_op#br#ed_cl#
#ed_op#br#ed_cl#小弟的另類計算:#ed_op#br#ed_cl#所有減去零對再減去兩對#ed_op#br#ed_cl#1-(#ed_op#sub#ed_cl#6#ed_op#/sub#ed_cl#C#ed_op#sub#ed_cl#3#ed_op#/sub#ed_cl#*2#ed_op#sup#ed_cl#4#ed_op#/sup#ed_cl#-#ed_op#sub#ed_cl#6#ed_op#/sub#ed_cl#C#ed_op#sub#ed_cl#2#ed_op#/sub#ed_cl#)/#ed_op#sub#ed_cl#12#ed_op#/sub#ed_cl#C#ed_op#sub#ed_cl#4#ed_op#/sub#ed_cl# = 16/33#ed_op#br#ed_cl#峰 寫到:[C(6,1)*C(5,2)*2*2]/C(12,4)