Consider the following table
The table is in which normal form?
Answer : C
Third Normal Form but not BCNF
See the dependencies
AB ---> CDE
C ---> B
C is not a Super key Here
1NF(yes): assume all attributes are atomic
2NF(yes): no partial functional dependency like A alone can derive C or D or E
3NF(yes): no transitive functional dependency or there is nothing like (non key)-->(non key)
BCNF(no): in non trivial FD C-->B , C is not a SuperKey.
It is 3NF
Bcz AB->CDE ,here we can clealy see that AB is super keys that's why it will be in 3NF and BCNF but C->B it is in 3NF not in BCNF that's why we can say that it will be in 3NF not in BCNF bcz both of them should be in BCNF not single one.