What is the probability that you and your brother have the s

What is the probability that you and your brother have the same Y-chromosome? What is the probability that you and your sister share at least one X-chromosome? What is the probability that you and your sister share two X-chromosomes?

Solution

1. only 1 because my father having only one Y chromosome

2. 1/4 because the probability of me to getting a X chromosome is half and the probability of my to get a X chromosome is half so the probability of Sharing at least one X chrosome will be 1/4.

3. Zero because i have only one X chromosome.