Set of natural numbers, A={x:x ϵ N} is a proper subset of which of the following?
All of the above.
A set 'A' is said to be a proper subset of B if A is a subset of B and A ≠ B i.e if
(i) Every element of A is an element of B
(ii) B has at least one element which is not an element of A.
In all the options, the above conditions are satisfied. So, set of natural numbers 'A' is a proper subset of whole numbers, real numbers, and integers.