3) Leo tosses a coin (not biased) 7 times, getting heads twice and tails five times. If he tosses it one more time, with what probability will he get heads?
(A) $\frac{1}{8} \quad$ (B) $\frac{1}{7}$
(C) $1-\frac{1}{2^{7}}$
(D) $\frac{35}{2^{7}}$
(E) $\frac{1}{2}$
## 3. The answer is $\mathbf{( E )}$.

With each coin toss, the probability of getting heads is the same, regardless of the outcomes of previous tosses. Since the coin is not biased, this probability is $1 / 2$. [Problem proposed by P. Leonetti]