A relation R is defined from {2;3,4,5} to {3, 6,7,10) by $x\mathrm{R}y\iff x$ is relatively prime to y. Then domain of R is 

The relation R is defiend as if $a$ is relatively prime to $b$ then $\left(a,b\right)\in R$ and vice versa

And the relation R is defined from $A=\left\{2,3,4,5\right\}$ to $B=\left\{3,6,7,10\right\}$

Hence, $R=\left\{\left(2,3\right),\left(2,7\right),\left(3,7\right),\left(3,10\right),\left(4,7\right),\left(5,3\right),\left(5,6\right),\left(5,7\right)\right\}$

The domaon or R is $\boxed{\left\{2,3,4,5\right\}}$