This would be a geometric probability distribution, so we would have:
for the second one:
the suns and lakers play a 7 game series. The suns have a 3/7 chance of winning each game and the lakers have a 4/7 chance of winning each game. Assume they play all 7 games.
A) Probability(suns win 4 games) =
B) Probability(lakers win 4 games) =