The ans given here is wrong;

i used here

declare @temp table (num int, numdesc varchar(50))

insert @temp select 1, 'one'

union select 2, 'two'

union select 3, null

union select 4, 'four'

union select 5, null

i) select count_big(*) from @temp

ii) select count_big(num) from @temp

iii) select count_big(numdesc) from @temp

iv) select count_big(all numdesc) from @temp

v) select count_big(distinct numdesc) from @temp

and the same result were from

a) i) and ii)

b) iii), iv) and v)