contestada

A few probability questions. Quickly please :) I have tried to do them but seem to be unable to figure these 2 out.

1). There are 7 red and 5 blue marbles in the bag. you randomly chooses one of the marbles. Without replacing the first marble, you choose a second marble. Find the probability of the events.
A. Choosing a red marble and then a blue marble.
B. Choosing a blue marble and then another blue marble.
C .Without replacing the first and second marble,you choose a blue marble, a red marble, and then another red marble.

2). A bag contains 6 red marbles, 4 blue marbles, 7 green marbles, and 3 yellow marbles. A marble is drawn from the bag and not replaced. Then a second marble is drawn. What is the probability that both marbles were red?
A 3/40
B 9/100
C 3/38
D 9/95

Respuesta :

1.choosing a red marble since the probability would be 7/12 but the blue would be 5/12 so red is most possible
2.the possibility of a red being chosen is 2/20=1/10

Otras preguntas