UGC NET Paper 1 GA 2017 Jan Solved Paper

This happens in Sub-altem (A + I or E + O) consider the follow:
All Trees are flowers (A)
Some Trees are flowers (I)
'Some Trees are flowers' is true, it is difficult to come up with a single venn diagram (because there is a possibility that some trees are not flowers)
In that situation, the universal positive (A) [All trees are flowers] will be undetermined because we can't draw a single venn diagram.