To solve the problem:

Problem Breakdown

The question states that the number of subsets of a set $B$ is given as 35. We are to find $n(B)$, which is the number of elements in set $B$.

Concept

The total number of subsets of a set with $n$ elements is $2^n$. This includes both the empty subset and the set itself.

Given: $2^n = 35$

Solving

However, $35$ is not a power of 2. There seems to be some confusion in the problem statement or its interpretation. Could you clarify or verify the question details? Or would you like me to explain a general method?