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

x	y
16	32
30	60
40	80
56	84

$\dfrac{x$1}{y1} = \dfrac{16}{32} = \dfrac{1}{2},\\[1em] \dfrac{x2}{y2} = \dfrac{30}{60} = \dfrac{1}{2},\\[1em] \dfrac{x3}{y3} = \dfrac{40}{80} = \dfrac{1}{2},\\[1em] \dfrac{x4}{y4} = \dfrac{56}{84} = \dfrac{2}{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.