Suppose that two fair (i.e., the probability of both Heads and Tails is 0.5) coins are tossed, and we observe the results. There are 4 possibilities: {H, H}, {H, T}, {T, H}, {T, T}. Assume a H wins us 1$, whereas a T no dollars.
1. What is the probability that I still have 0 dollars after 5 trials?
2. What is the probability that the first time I get a Heads and a Tails together (either {H, T} or {T, H}) is after 5 trials?
3. What is the probability that I make at least 10 dollars after 10 trials?