Q1.
Have you wondered what makes an event like rain random?
Answer
Rain is random because it depends on too many interacting factors — temperature, humidity, wind patterns, pressure — and it is so sensitive to them that no measurement is ever complete or exact enough to settle the question in advance.
Why it happens: "random" here does not mean "without a cause". Every raindrop has a physical cause. It means that the causes are so many, and so finely balanced, that a tiny difference in today's air — one we could never measure — leads to a different answer tomorrow. So the exact time and place of rainfall cannot be predicted with certainty, however good the instruments are.
This is why the sentence "it will rain tomorrow" cannot be given the value 0 or 1 in advance. But it is not useless either: past records let us count how often rain followed conditions like today's, and that relative frequency is a genuine, checkable estimate of the probability.
Tip: compare rain with the toss of a coin. A coin has just two outcomes and an obvious symmetry, so we can reason out P = 1/2 without any data. Rain has no such symmetry, so its probability must be measured from records rather than argued from a picture. Both are random; only one can be handled theoretically.