What we're gonna do is to find the first 'n', how are we gonna do that? by applying the cross product rule.
Cross product rule involves 2 ratios or fractions separated by an equal sign. It is where the numerator of the other is multiplied to the denominator of the another fraction/ratio involved until we get the unknown.
First, Let's find the pair of ratios from the given that would only shows us one unknown,
12/66 = 22/n
Then, apply cross product rule.
12(n) = 66(22)
n = 121
Next, let's find the next fraction having one unknown and let's use the previous fraction/ratio with the first value of 'n':
n/55 = 22/121
n(121) = 55(22)
n = 10
Then same goes for finding the value for the last 'n':
2/n = 10/55
(55)2 = 10(n)
n = 11
For other approach in solving the problem, refer below for the links: