Question

If $x$ and $y$ are directly proportional, find the value of $x_1,x_2$ and $y_1$ in the table given below:

$x$	$3$	$x_1$	$x_2$	$10$
$y$	$72$	$120$	$192$	$y_1$

Answer 1

Since $xandy$ are directly proportional, we have $\frac{x}{y}=Constant$

So,

$\frac{3}{72}=\frac{x_1}{120}=\frac{x_2}{192}=\frac{10}{y_1}$

Now,

$\Rightarrow \frac{3}{72}=\frac{x_1}{120}$

$\Rightarrow x_1\times 72=3\times 120$

$\Rightarrow x_1=\frac{120\times 3}{72}=5$

Now,

$\Rightarrow \frac{3}{72}=\frac{x_2}{192}$

$\Rightarrow x_2\times 72=3\times 192$

$\Rightarrow x_2=\frac{576}{72}=8$

Now,

$\Rightarrow \frac{3}{72}=\frac{10}{y_1}$

$\Rightarrow y_1\times 3=10\times 72$

$\Rightarrow y_1=\frac{720}{3}=240$
$\therefore x_1=5,x_2=8,y_1=240$