In the following table, do x and y vary directly:

x	y
27	81
45	180
54	216
75	225

$\dfrac{x$1}{y1} = \dfrac{27}{81} = \dfrac{1}{3},\\[1em] \dfrac{x2}{y2} = \dfrac{45}{180} = \dfrac{1}{4},\\[1em] \dfrac{x3}{y3} = \dfrac{54}{216} = \dfrac{1}{4},\\[1em] \dfrac{x4}{y4} = \dfrac{75}{225} = \dfrac{1}{3},\\[1em]

$\Rightarrow \dfrac{x$1}{y1} ≠ \dfrac{x2}{y2} = \dfrac{x3}{y3} ≠ \dfrac{x4}{y4} = not a constant

Hence, x and y are not in direct variation.