Duas bolas são retiradas de uma sacola contendo bolas brancas 5 e pretas 7 aleatoriamente. Qual a probabilidade de serem de cores diferentes?

Responda:

$\frac{35}{144} + \frac{35}{144} = \frac{70}{144}$ $35/144+35/144 =70/144$

Explicação:

$assuming replacement of the first ball$ $"assuming replacement of the first ball"$

$P (white) = \frac{5}{12}$ $P("white")=5/12$

$P (black) = \frac{7}{12}$ $P("black")=7/12$

$P (white and black)$ $P("white and black")$

$= \frac{5}{12} \times \frac{7}{12} = \frac{35}{144}$ $=5/12xx7/12=35/144$

$P (black and white)$ $P("black and white")$

$= \frac{7}{12} \times \frac{5}{12} = \frac{35}{144}$ $=7/12 xx5/12 = 35/144$