原式=
1
-------------------------------------
24×35×46＋35×46×57＋46×57×68
----------------------------------
35×46×57
1
= ----------------
24 68
---- +1 + ----
57 35
1 1995 665
= -------- = ---- = -----
6711 6711 2237
----
1995
速算及巧算(35×46×57)÷(24×35×46＋35×46×57＋46×57×68)