Search

Question 1 of 8

No calculator

A chance experiment first chooses a sleeve and then chooses one card from that sleeve

The first table gives the first-stage choice counts. The second table gives the card counts for each first-stage choice

The first-stage counts set the probabilities of the source branches
First-stage choiceCount
Sleeve R7
Sleeve P3
The card counts are conditional on the first-stage choice
First-stage choiceblackbluewhiteRow total
Sleeve R37414
Sleeve P73717

The ordered outcomes form the sample space \(S\). Let \(E\) be the event that at least one of these is true: the first choice is Sleeve P; the final card is white

Each first-stage count represents that many equally likely selection tickets. After choosing a source, select one of its items uniformly at random. Calculate the missing probabilities marked ? from these counts

A directed probability tree. Its branches are Start to Sleeve R is labelled 7/10; Sleeve R to (Sleeve R, black) is labelled 3/14; Sleeve R to (Sleeve R, blue) is labelled 1/2; Sleeve R to (Sleeve R, white) is labelled ?; Start to Sleeve P is labelled 3/10; Sleeve P to (Sleeve P, black) is labelled ?; Sleeve P to (Sleeve P, blue) is labelled ?; Sleeve P to (Sleeve P, white) is labelled ?.7/103/141/2?3/10???StartSleeve R(Sleeve R, black)(Sleeve R, blue)(Sleeve R, white)Sleeve P(Sleeve P, black)(Sleeve P, blue)(Sleeve P, white)

If needed, scroll sideways to follow each complete path

Read stages from left to right. Each edge shows a branch probability or a missing value marked ?. The terminal labels record complete ordered outcomes
(a)1 mark

Which calculation plan gives the probability asked for?

(b)4 marks

Fill the missing branch and path probabilities as exact fractions

(c)1 mark

Find \(\Pr(E)\) as an exact fraction

Format: exact fraction