What point is best for alpha? And why?

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

If you flip a coin 3 times, what is the probability of flipping heads 3 times? a. p(3 heads) = 3/8 b. p(3 heads) = 1/6 c. p(3 heads) = 1/8 d. p(3 heads) = 1/2

Math i have no idea how to do a and b