Expectancy and variation of coin toss set

Question

What is expectancy in the sense of sample mean and variance of this coin toss set

$$S=[1,1,0,1,0]$$

probability of $P(x=1)$ is $p$

Variance is $$var(S) = E(S^2) - E(S)^2$$

but I don't know how to calculate $E(S^2)$ given there are many 1's

Answer 1

If you can calculate E(S), the it happens $E(S^2)=E(S)$, since 0 and 1 are equal to their squares.