Sum[Binomial[40, n]*(1/1000)^(n−1)*(999!/((999−40+n)!*1000^(999−41+n)))^(39−n), {n, 2, 39}]Sum[Binomial[40, n]*(1/1000)^(n−1)*(999!/((999−40+n)!*1000^(999−41+n)))^(39−n), {n, 2, 39}]

• Natural Language
• Math Input