'No red is black' is equivalent to
'No black is red' and this is equivalent to
'Red is not black'.
'All red are black' is negative proposition.
Hence, only conclusion (i) and (iv) are correct.
'No black is red' and this is equivalent to
'Red is not black'.
'All red are black' is negative proposition.
Hence, only conclusion (i) and (iv) are correct.


