Probability is the section of the gaokao maths paper that most rewards careful reading. The arithmetic is not hard; deciding which formula applies is, and that is almost always a reading problem rather than a maths one.
Ask two questions before anything else: is this with or without replacement, and does order matter? Those two answers tell you whether you are counting combinations, permutations or something else entirely.
For conditional probability, write P(A|B) = P(A∩B) / P(B) out in full before you substitute any numbers. Half the mistakes on this topic come from calculating P(A∩B) and reporting it as P(A|B).
Expected-value questions almost always come down to E(X) = Σ xᵢ · pᵢ. Build the distribution table first, then write the formula.
For the normal-distribution question at the end of the section, memorise the three intervals: μ±σ ≈ 68.3%, μ±2σ ≈ 95.4%, μ±3σ ≈ 99.7%. The question tests whether you can read a table, not whether you can integrate.