edited by
16,627 views
54 votes
54 votes

From the following instance of a relation schema $R(A,B,C)$, we can conclude that:

$$\begin{array}{|l|l|}\hline \textbf{A} & \textbf{B} & \textbf{C} \\\hline  \text{1} & \text{1} & \text{1} \\   \text{1} & \text{1} & \text{0} \\ \text{2} & \text{3} & \text{2} \\ \text{2} & \text{3} & \text{2} \\\hline \end{array}$$

  1. $A$ functionally determines $B$ and $B$ functionally determines $C$
  2. $A$ functionally determines $B$ and $B$ does not functionally determine $C$
  3. $B$ does not functionally determine $C$
  4. $A$ does not functionally determine $B$ and $B$ does not functionally determine $C$
edited by

6 Answers

–2 votes
–2 votes
When value of A is 1,B is 1.When value of A is 2,B is 3.So A functionally determines B.

When value of B is 1,C is 1 and in another case C is 0.So B does not functionally determine C.

Hence,the answer is B.
–3 votes
–3 votes
Ans will be B

Here A->B satisfies(for same value in A , B also gives unique value)

B->C not satisfies(when B is 1 , C gives two values 1,0)
Answer:

Related questions