( 1 - 1/99) x ( 1 - 1/100) x...(1 - 1/2006)
Giải thích
1-199 x 1 - 1100....1-12006
=(9999-199)x(100100-1100)....(20062006-12006) = 9899x99100....20052006=982006
1-199 x 1 - 1100....1-12006
=(9999-199)x(100100-1100)....(20062006-12006) = 9899x99100....20052006=982006