Your friend is tossing a coin. He says that heads and tails are equally likey outcomes, so the probability of getting heads is 50/50. Explain your friends error.
There is no error if you are talking about just one toss.
Prob. of head = 50%
Prob. of tail = 50%
See http://www.members.cox.net/dagershaw/lol/Odds.html
Your friend's error lies in assuming that the probability of getting heads and tails when tossing a fair coin is always 50/50. However, it's important to note that the probability is not solely dependent on what has happened previously, but rather on the inherent nature of the coin itself.
To understand the probability of getting heads or tails, we need to consider the concept of a fair coin. A fair coin is one that has two equally likely outcomes - heads or tails. Assuming the coin is unbiased and symmetrical, each side has an equal chance of landing face-up when flipped.
The probability of an event occurring is calculated by dividing the number of favorable outcomes by the total number of possible outcomes. In the case of a fair coin toss, there are two possible outcomes - heads (H) or tails (T). Therefore, the probability of getting heads is 1 out of 2, or 1/2, and the same goes for the probability of getting tails.
It's worth noting that even though the theoretical probability is 1/2, it doesn't guarantee that when you flip the coin, you will always get a 50/50 distribution of heads and tails. This is because each toss is an independent event, and previous outcomes do not impact future ones. Therefore, it's possible to have a series of tosses that deviates from a 50/50 split.
So, in summary, your friend's error is assuming that every toss will always result in a 50/50 probability of heads or tails, when in reality, the theoretical probability is 1/2, but the actual observed outcomes may vary.