You and your brother always flip a special golden dollar coin to decide who gets to select the music when the two of you are in the car. The coin has come up heads (in your brother’s favor) on 8 of the last 10 flips. Do 10 flips provide convincing evidence that your brother is using an unfair coin to gain an advantage?

Yes, the probability of flipping heads with a fair coin is 0.5. He should have gotten heads exactly 5 times.
No, there is no way to determine the probability of flipping heads.
Maybe, if the coin comes up tails on 8 of the next 10 flips, then he is using a fair coin.
No, 10 trials (flips) is not enough evidence to determine if the coin is fair. We would need many, many more flips to determine the true proportion of heads for this coin.