Analysis and Approaches for IBDP Maths Ebook 1 | Page 250

Your Practice Set – Analysis and Approaches for IBDP Mathematics
Exercise 81
1. Let C and D be independent events, with
0 < k < 0.5.
P( C) 2k
2
� and
P( D) � 3k
2
, where
(a) Write down an expression for P( C� D)
in terms of k .
(b) Given that P( C� D)=0.0096
, find k .
(c) Find P( D� | C)
.
[2]
[2]
[3]
2. Let E and F be independent events, with
P( E) 4
3
� k and P( F)
� k, where
1
0 �k
� .
2
(a) Write down an expression for P( E� F)
in terms of k .
(b) Given that
(c) Find P( E� F)
.
1
P( E� F) = , find k .
2500
[2]
[2]
[2]
3. Let A and B be independent events, with P( A) � 2k
and P( B) � 1.5P( A)
, where
0 < k < 0.5. It is given that P( A� B) � 6k
� 1.
(a) Find k .
(b) Find P( B| A ) .
4. Consider the independent events A and B . Given that P( B) � 3P( A)
, and
P( A�B) � 0.93 , find P( B ) .
[5]
[2]
[7]
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