Question

a bag contains 5 white and 5 black marbles. you pick 2 marbles at random, one after the other without replacing the first. Draw a weighted tree diagram showing all the outcomes. what is the probability that you pick one marble of each colour?

Answer 1

Can you now calculate the probability of picking W - B or B - W ?

Answer 2

The probability of picking W - B is \[\frac{1}{2}\times \frac{5}{9}\]
The probability of picking B - W is \[\frac{1}{2}\times \frac{5}{9}\]
The probability of picking W - B or B - W is
\[(\frac{1}{2}\times \frac{5}{9})+(\frac{1}{2}\times \frac{5}{9})=?\]

Answer 3

5/9. thanks so much - sorry have been away from the computer

Answer 4

You're welcome :)