Question

A bag contains 8 blue marbles and 4 red marbles. Ray selects two marbles from the bag in succession, without replacement. (a) Complete the missing probabilities on the tree diagram below. 8/12 blue 7/11 blue — red — blue 4/12 red 3/11 red (b) Determine the probability of: (i) Ray selecting two red marbles. (ii) Ray selecting two marbles of different colour.

          A bag contains 8 blue marbles and 4 red marbles.
Ray selects two marbles from the bag in succession, without replacement.
(a) Complete the missing probabilities on the tree diagram below.
8/12 blue
7/11 blue
— red
— blue
4/12 red
3/11 red
(b) Determine the probability of:
(i) Ray selecting two red marbles.
(ii) Ray selecting two marbles of different colour.

A bag contains 8 blue marbles and 4 red marbles.
Ray selects two marbles from the bag in succession, without replacement.
(a) Complete the missing probabilities on the tree diagram below.
8/12 blue
7/11 blue
— red
— blue
4/12 red
3/11 red
(b) Determine the probability of:
(i) Ray selecting two red marbles.
(ii) Ray selecting two marbles of different colour.

Added by Kevin R.

Elementary Statistics a Step by Step Approach

Allan G. Bluman 9th Edition

Instant Answer

Solved by Expert Audrey Fong

05/04/2022

Step 1

The total number of marbles in the bag is $b + r$. (i) For Ray to select two red marbles, he must first select a red marble and then select another red marble. The probability of selecting a red marble on the first draw is $\frac{r}{b+r}$. After selecting one red Show more…

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A bag contains 8 blue marbles and 4 red marbles. Ray selects two marbles from the bag in succession, without replacement. Complete the missing probabilities on the tree diagram below. Determine the probability of: (i) Ray selecting two red marbles. (ii) Ray selecting two marbles of different colour.