Question

Let R be the relation defined on the set N of natural numbers by the rul xRy iff x + 2y = 8, then domain of R is

• A. {2, 4, 8}
• B. {2, 4, 6}
• C. {2, 4, 6, 8}
• D. {1, 2, 3, 4}

Answer 1

The correct option is B {2, 4, 6}

$x,y,ϵN\Rightarrow x,y=1,\mathrm{2...}$

As $x+2y=8$ & $y=1,\mathrm{2...}$

$\Rightarrow x=\{6,4,2\}$ for $y=1,2,3$