Out of three offspring, one is tall, and two are intermediate.
When there are more than two outcomes of a trial, the distribution of all possibilities is described by the multinomial distribution. Consider an additive pair of alleles A and a, where an offspring of a cross between two Aa individuals is tall (with genotype AA) with probability 0.25, is intermediate (with genotype Aa) with probability 0.5, and is short (with genotype aa) with probability 0.25. Count up all possible ways for the following to happen and find the associated probabilities.