a.
We have a total of 4 three cards and 4 jack cards, this means that we have 8 favorable outcomes out of 52, hence we have that:
[tex]P=\frac{8}{52}=\frac{2}{13}[/tex]Therefore the probability is 2/13.
b.
We have a total of 26 red cards and two more black fives, this means that we have a total of 28 favorable outcomes, hence:
[tex]P=\frac{28}{58}=\frac{7}{13}[/tex]Therefore the probability is 7/13