Answer :

toporc
(i)[tex]P(zero\ bombs)=\frac{20C0\times 380C10}{400C10}=0.595[/tex]

(ii)[tex]P(zero\ bombs)=\frac{40C0\times 360C10}{400C10}=0.344[/tex]
     P(one or more bombs) = 1.000 - 0.344 = 0.656