(1+1/2002+1/2004+1/2006)X(1/2002+1/2004+1/2006+1/2008)X(1/2002+1/2004+1/2006)答对可获赏金

(1+1/2002+1/2004+1/2006)X(1/2002+1/2004+1/2006+1/2008)X(1/2002+1/2004+1/2006)答对可获赏金
(1+1/2002+1/2004+1/2006)X(1/2002+1/2004+1/2006+1/2008)X(1/2002+1/2004+1/2006)
答对可获赏金

(1+1/2002+1/2004+1/2006)X(1/2002+1/2004+1/2006+1/2008)X(1/2002+1/2004+1/2006)答对可获赏金
最后一个式子缺失1/2008
设1/2002+1/2004+1/2006=x
1/2002+1/2004+1/2006+1/2008=y
（1+1/2002+1/2004+1/2006）*（1/2002+1/2004+1/2006+1/2008）-（1+1/2002+1/2004+1/2006+1/2008）* (1/2002+1/2004+1/2006)
=(1+x)y-(1+y)x
=y+xy-x-xy
=y-x
=1/2008