Question

Observe the following tables and find if $x$ and $y$ are directly proportional:

$x$	$5$	$8$	$12$	$15$	$18$	$20$
$y$	$15$	$24$	$36$	$60$	$72$	$100$

Answer 1

1/It is given that,
$x/y=5/15=1/3$
Similarly,
$x/y=8/24=1/3$
$x/y=12/36=1/3$
But, $x/y=15/60=1/4$
$x/y=18/72=1/4$
$x/y=20/100=1/5$ which is not equal to $1/3$
So, $x/y$ is not constant.
Hence, $x$ and $y$ are not directly proportional.