The problem asks to determine the number of subsets of a set $C$, where $n(C) = 7$.

Solution:

The formula to calculate the number of subsets of a set with $n$ elements is:

$2^n$

Here, $n(C) = 7$, so:

$\text{Number of subsets} = 2^7 = 128$

Final Answer:

The number of subsets of $C$ is 128.

Would you like more explanation or help with related concepts?

Here are five related questions to expand on this topic:

1. What is the formula to calculate the number of proper subsets of a set?
2. How many elements would a set need to have 64 subsets?
3. What is the difference between subsets and proper subsets?
4. How do we calculate the number of subsets if the set has duplicate elements?
5. Can you calculate the subsets of a set with $n(C) = 10$?

Tip: For every element added to a set, the total number of subsets doubles!