A recessive inherited disorder in llamas is caused by the faulty allele $f$. The normal allele is $F$. A llama with genotype $ff$ has the disorder, and a llama with genotype $Ff$ is unaffected.

Two llamas with genotype $Ff$ are used to produce offspring. For each mating in a breeding programme, one unaffected offspring from this cross is selected at random and mated with a llama known to have genotype $Ff$.

These matings produced 24 offspring in total. Of these, 7 had the disorder.