[Discrete Maths]Finding out if certain functions can define probabilities

This honestly makes it so much easier to understand holy crap.

I'm not sure if you actually want me to answer the questions or if you just translated them from symbols to normal text, but my answers would be:

If I told you that I had a coin, and that the probability of heads is 0.75 and the probability of tails is 0.75, would you believe me?

Not quite sure, as the probability doesn't add up to 1 (0.75+0.75 = 1.5) however, the chances of getting a head or tail on a normal coin are both equal, and they are also equal in this instance (both 0.75), so I'm not quite sure

If I told you that I had a four sided die, and that the probability of rolling 1 to 4 is 0.2, 0.15, 0.15 and 0.3, would you believe me?

No, because the probabilities of all the events add up to 0.8, meaning that 0.2 of something isn't there.

How about 0.2, 0.35, 0.15, 0.3?

Yes, because they add up to 1 this time.

If you had a 3 sided die somehow, and I said the probabilities are 0.4, 0.8 and -0.2, would you believe me?

Not quite sure on this one either, as I dont think you can have a -0.2 chance of something happening, however, if you add them all up, the probability does add up to 1.

/r/learnmath Thread Parent