Shortest Distance between Two Skew Lines

Q. The shortest distance between the lines
$\frac{x-3}{3}=\frac{y-8}{-1}=\frac{z-3}{1}$ and
$\frac{x-3}{-3}=\frac{y-7}{2}=\frac{z-6}{4}$

1. $\sqrt{10}$
2. $2\sqrt{20}$
3. $3\sqrt{30}$
4. $4\sqrt{40}$

Q. The shortest distance between the lines
$\frac{x-3}{3}=\frac{y-8}{-1}=\frac{z-3}{1}$ and
$\frac{x-3}{-3}=\frac{y-7}{2}=\frac{z-6}{4}$

1. $\sqrt{10}$
2. $2\sqrt{20}$
3. $3\sqrt{30}$
4. $4\sqrt{40}$

Q. The shortest distance between the lines
$\frac{x+1}{7}=\frac{y+1}{-6}=\frac{z+1}{1}$ and
$\frac{x-3}{1}=\frac{y-5}{-2}=\frac{z-7}{1}$ is

1. 11
2. 12
3. $2\sqrt{29}$
4. $2\sqrt{30}$

Q. If equations of two non intersecting lines are -
$\frac{x-x_1}{l_1}=\frac{y-y_1}{m_1}=\frac{z-z_1}{n_1}$ & $\frac{x-x_2}{l_2}=\frac{y-y_2}{m_2}=\frac{z-z_2}{n_2}$ then the shortest distance between them will be -

1. $\frac{1}{\sqrt{\Sigma (l_1{m}_2-l_2{m}_1{)}^2}}\left|\begin{array}{ccc}x1& y1& z1\\ l1& m1& n1\\ l2& m2& n2\end{array}\right|$
2. $\frac{1}{\sqrt{\Sigma (l_1{m}_2-l_2{m}_1{)}^2}}\left|\begin{array}{ccc}x2-x1& y2-y1& z2-z1\\ l1& m1& n1\\ l2& m2& n2\end{array}\right|$
3. $\frac{1}{\sqrt{\Sigma (l_1{m}_2-l_2{m}_1{)}^2}}\left|\begin{array}{ccc}x2& y2& z2\\ l1& m1& n1\\ l2& m2& n2\end{array}\right|$
4. None of these

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

1. $2\sqrt{30}$
2. $\frac{7}{2}\sqrt{30}$
3. $3$
4. $3\sqrt{30}$