By definition of the [tex]\ell_p[/tex] norm,
[tex]\|x-y\|_1 = \displaystyle \sum_{i=1}^3 |x_i-y_i| = |5-3|+|2-3|+|4-2| = \boxed{5}[/tex]
[tex]\|x-y\|_2 = \displaystyle \left(\sum_{i=1}^3 |x_i-y_i|^2\right)^{\frac12}= \sqrt{|5-3|^2+|2-3|^2+|4-2|^2}= \sqrt9= \boxed{3}[/tex]
[tex]\|x-y\|_\infty = \max\limits_{i} |x_i-y_i| = \max\left\{|5-3|,|2-3|,|4-2|\right\}=\boxed{2}[/tex]
and so x and y are closest together with p = infinity and furthest apart with p = 1.