Question

In a certain computer game, the computer can make 1 of 4 moves, which it chooses randomly. According to the game manual, the probability it will make 1 of the moves is 0.5, the probability it will make 2 of the remaining moves is 0.25, and the probability it will make the last move is unknown, but nonzero. Why can the player immediately know that these probabilities are incorrect?

Answer 1

because 0.5 + 0.25 + 0.25 is already one. It states in the question that the chance is nonzero, however 1-1 is 0

Answer 2

Because probability is based on 1, and the sum of the three situations is already 1.

Explanation:

When you are calculating the probability of something happening you have a finite number of possibilities, and the sum of those would be always 1 when you are doing a precentage possibility, in this example you have 50% chance of a movement happening, 25% of each of the other two, that adds up to a 100% of the chances you have to get something, which aint possible.