UPSC NDA Math Model Paper 3

Given, x={4n−3n−1:n∈N}, where N is the set of natural numbers,
⇒ X = {0, 9, 54,....}
and Y = {9(n - 1) : n ∈ N}, where N is the set of natural numbers,
⇒ Y = {0, 9, 18, 27,....}
Here, all elements of X is contained in set Y.
Hence, X is subset of Y.
X ⊂ Y
Hence, if x = {4n - 3n - 1: n ∈ N} and Y{9(n - 1) : n ∈ N}, where N is the set of natural numbers, then X ⊂ Y