The value of x when y = 9 is 36
Solution:
Given that, x and y vary directly,
And x = 12 when y = 3,
We have to find what will be the value of x when y = 9
Now from the given information,

x = cy ---- eqn 1
where "c" is the proportionality constant
Now, substitute x = 12 and y = 3 in (1)
12 = c(4)
c = 3
Then, (1) ⇒ x = 4y
So, when y = 9 ⇒ x = 4(9) ⇒ x = 36
Hence, x value is 36 when y value is 9, so 1st option is correct