Set S has 7 elements.

Question

Set $S$ has 7 elements. A non-empty subset $A$ and element $x\in S$ are chosen at random. Find $P(x\in A)$.

Accepted Answer

Subsets containing a fixed element: $2^6=64$, out of $2^7-1=127$ non-empty subsets.

$$P = \frac{64}{127}$$

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