AND Rule
P(A and B) = P(A) × P(B) for independent events
OR Rule
P(A or B) = P(A) + P(B) − P(A and B)
Complement
P(not A) = 1 − P(A)
Hardy–Weinberg
p² + 2pq + q² = 1 ; p + q = 1
Punnett Square
Cross genotypes → predict offspring ratios
Conditional
P(A|B) = P(A and B) / P(B)