A hint to get started
Retain the exceptional all-blue score in the conditional game
A box contains 2 red balls,3 green balls and x blue balls, with integer . A contestant chooses 5 balls without replacement. S is the number of green balls plus three times the number of red balls. Blue balls score nothing unless all 5 balls are blue, in which case S=25.
(i) Show that . marks
(ii) Given , calculate x. marks
(iii) Complete the distribution table. marks
| s | Given |
|---|---|
| 1 | to find |
| 2 | |
| 3 | |
| 4 | to find |
| 5 | |
| 6 | |
| 7 | to find |
| 8 | |
| 9 | |
| 25 | to find |
(iv) Evaluate and find . marks
(v) Find the probability that no green balls are drawn, given . marks
[2017/CJC/II/10]
CJC · Review problems · Question 9
The all-blue draw is an exceptional score 25, not score 0.