The answer is (B) every six months
Answer:25%
Explanation:
Given
Grandfather had Huntington disease
So Probability that the father had inherited the disease is 
So the Probability that the young man will get the disease is equal to half of Probability that his Father had inherited the disease
i.e. 
=25%
Answer:
253 divided by 2 because radius is the half
so the answer is 126.5