Manx cats are tailless and when crossed with one another produce on average 1 long-tailed (wild type) cat for every 2 Manx. The M (Manx) allele is lethal in homozygous condition due to problems arising during development. Thus, a MM genotype is lethal, a Mm cat is Manx (tailless), whereas a mm cat is wild type with a long tail. A population is composed of Manx and wild type cats in a 1:1 ratio.
What is the frequency of m allele of this population?