Question

If x and y vary directly, and x = 10 when y = 3, what will be the value of x when y = 9?

x = ??? a0

Answer 1

y=3 x=10
X3 X3
y=9 x=30

Answer 2

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

`y\propto x\\\\\Rightarrow y=px,~~~~~~~~~~~\textup{[where p is the proportionality constant]}.`

When x = 10, y = 3, then

`3=p*10\\\\\Rightarrow p=(3)/(10).`

So, the relation between x and y will be

`y=(3)/(10)x\\\\\Rightarrow x=(10)/(3)y.`

Therefore, when y = 9, then

`x=(10)/(3)*9=30.`

Thus, the required value of x is 30.