Answer:
a. In image attached.
b. 25% or a 1 in 4 chance.
c. 75% or a 3 in 4 chance.
Step-by-step explanation:
B = Dominant (brown gene)
r = Recessive (red gene)
If two parents both have Br genes, they will both have brown hair.
The Punnet square will look like the image attached.