What is the value of 'x' in 55 : 11 :: x : 6?

Given,  55 : 11 ::  x : 6.

We know that, the product of means = the product of extremes.

So, $11\mathrm{x}=55\times 6$.

$\Rightarrow \mathrm{x}=\frac{330}{11}$

$\Rightarrow \mathrm{x}=30$

So, the value of 'x' is 30.