Analysis and Approaches for IBDP Maths Ebook 1 | Page 265

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4. On a shelf there are two tins, one red and one blue. The red tin contains two orange
candies and eight apple candies, and the blue tin contains six orange candies and four
apple candies. Oliver randomly chooses either the red or the blue tin and randomly selects
a candy.
Let R be the event that the red tin is chosen, and A be the event that an apple candy is
selected.
The information above is shown on the following tree diagram.
(a)
Find
(i) P( R�� A)
;
19
(b)
(ii) P( A ) .
Find the probability that
[4]
(i)
an orange candy is selected from the red tin;
(ii) he selected a candy from the red tin, given that the candy selected is an
apple candy.
[5]
Oliver designed a game by using the above two tins. If an orange candy is chosen, then
the participant will get 4 tokens. If an apple candy is chosen, no tokens would be awarded.
Let X be the total number of tokens of three different participants of the game.
(c)
(d)
Copy and complete the probability distribution table.
X 0 4 8 12
P( X � x)
36
125
Find the expected expenditure.
[3]
[2]
www.seprodstore.com
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