Question

there are 3 black marbles in and 4 red marbles in a bag. what is the probability that you will pick two black marbles put of the bag without replacing the first one?

Answer 1

$|\Omega|=7\cdot6=42\\ |A|=3\cdot2=6\\\\ P(A)=\dfrac{6}{42}=\dfrac{1}{7}\approx14\%$