The shortest distance between the lines ${{x - 3} \over 3} = {{y - 8} \over { - 1}} = {{z - 3} \over 1}$ and ${{x + 3} \over { - 3}} = {{y + 7} \over 2} = {{z - 6} \over 4}$ is :

Question

The shortest distance between the lines

${{x - 3} \over 3} = {{y - 8} \over { - 1}} = {{z - 3} \over 1}$ and

${{x + 3} \over { - 3}} = {{y + 7} \over 2} = {{z - 6} \over 4}$ is :

${7 \over 2}\sqrt {30} $