Question

Alejandra's DVD movie collection includes 4 horror selections, 4 science fiction, 3 drama, 3 thrillers, and 2 comedies. If she picks two DVD's for an evening, without replacing them, what is the probability she will pick two thriller selections?

Answer 1

`\displaystyle |\Omega|=\binom{16}{2}=(16!)/(2!14!)=(15\cdot16)/(2)=120\\ |A|=\binom{3}{2}=(3!)/(2!)=3\\\\ P(A)=(3)/(120)=(1)/(40)=2,5\%`