Answer: The required value of x is 30.
Step-by-step explanation: Given that the variables x and y varies directly. And, x = 10 when y = 3.
We are to find the value of x when y = 9.
Given that x and y varies directly. So, we have
[tex]y\propto x\\\\\Rightarrow y=px,~~~~~~~~~~~\textup{[where p is the proportionality constant]}.[/tex]
When x = 10, y = 3, then
[tex]3=p\times10\\\\\Rightarrow p=\dfrac{3}{10}.[/tex]
So, the relation between x and y will be
[tex]y=\dfrac{3}{10}x\\\\\Rightarrow x=\dfrac{10}{3}y.[/tex]
Therefore, when y = 9, then
[tex]x=\dfrac{10}{3}\times9=30.[/tex]
Thus, the required value of x is 30.
