Please Help : Probablity Stat

[math210kn]

A professor is making a Math Olympiad team of 3 boys and 3 girls from a group
of students which has 6 girls and 8 boys. How many ways can he make a team this way
(a) Without any restrictions?
(b) If two of the boys refuse to be on the same team?
(c) If one girl and one boy refuse to be on the same team?