If selfing starts in a previously randomly mating population composed of 0.50 heterozygotes, what is the frequency of heterozygotes after three generations of selfing

So after the third generation of selfing, 0.0625 population will be hetero zygous.

Explanation:

Selfing or in another term self-breeding lead to the loss of heterozygosity which ultimately decreased the genetic variation of any population. Selfing in each successive generation cause the loss of 50% heterozygosity from parental one

if a randomly mating population start selfing with 50% heterozygosity then after three generations following result will be obtained

F1-0.25%

F2-0.125%

F3-0.0625%