A squad of \(20\) boys, which includes \(2\) sets of twins, is available for selection for a cricket team of \(11\) players.

Calculate the number of different teams that can be selected if

(i) there are no restrictions,

(ii) both sets of twins are selected,

(iii) one set of twins is selected but neither twin from the other set is selected,

(iv) exactly one twin from each set of twins is selected.