1. **State the problem:** We are given a set $B = \{1, 2, 3, 4\}$ and need to find how many subsets can be formed from this set. 2. **Formula used:** The number of subsets of a set with $n$ elements is given by the formula: $$\text{Number of subsets} = 2^n$$ This is because each element can either be included or excluded from a subset, giving 2 choices per element. 3. **Apply the formula:** Here, $n = 4$ since the set $B$ has 4 elements. $$2^4 = 16$$ 4. **Interpretation:** This means there are 16 different subsets of the set $B$, including the empty set and the set $B$ itself. **Final answer:** There are 16 subsets of the set $B = \{1, 2, 3, 4\}$.