Question

Observe the values and find the quantities which are in direct proportion
$x:\left[46810\right]y:\left[2345\right]z:\left[1234\right]$

• A. x & y
• B. y & z
• C. x & z
• D. None of these

Answer 1

The correct option is A x & y

By definition of direct proportion,

$a\alpha b$ i.e. $a=Kb$ where $K$ is constant of proportionality

$\therefore \frac{a}{b}=K$ ........ equation $1$

From given example, consider

$\frac{x}{y}=\frac{4}{2}=\frac{6}{3}=\frac{8}{4}=\frac{10}{5}=2$

where as

$\frac{x}{z}=\frac{4}{1}\ne \frac{6}{2}\ne \frac{8}{3}\ne \frac{10}{4}$

$\therefore$ $x$ and $y$ obey the equation $1$

Hence $x$ and $y$ are in inverse proportion.

Answer is A