Question

Let $A =\{1,2,3,4,6\} .$ If $R$ is the relation on A defined by $\{(a, b): a, b \in A, b$ is exactly divisible by a $\}$.
Assertion : The relation $R$ in Roster form is $\{(6,3),(6,2)$, $(4,2)\} .$
Reason : The domain and range of $R$ is $\{1,2,3,4,6\}$.

• A. Assertion is correct, Reason is correct; Reason is a correct explanation for assertion.
• B. Assertion is correct, Reason is correct; Reason is not a correct explanation for Assertion
• C. Assertion is correct, Reason is incorrect
• D. Assertion is incorrect, Reason is correct.

Answer 1

Answer: (D)

In Roster form $R =\{(1,1),(1,2),(1,3),(1,4),(1,6)$
$(2,4),(2,6),(2,2),(4,4),(6,6),(3,3),(3,6)\}$
Domain of $R =$ Set of first element of ordered pairs in
$R =\{1,2,3,4,6\} $
$\therefore $ Range of $R =\{1,2,3,4,6\}$