Page 83 - Math SL HB Sem 3

PAPER 2

l. The letters of the word PROBABILITY are wriften on 1l cards as shown below.

P R o B A B I L I T Y

Two cards are drawn at random without replacement.
Let.{ be the event lhe first card drawn is the letter A.
Let ,8 be the event the second card drawn is the letter B.

(a) Find P(l).
(l)
(b) Find P(B ll).
t2)

(c) Find P(A I B).
(3)
(Total 6 marks)
) Consider the events A and B, wbercP(A) :0.5, P(B) = 0.7 and P(l n B) = 0.3.

The Venn diagram below shows the events ,4 and B, and the probabilities p, g and r.

B
_-1

(a) Write down the value of

(i) pi

(ii) q;

(iii) r.
(3)

(b) Find the value ofP(l A').
I
(2t

(c) t{ence, or otherwise, show thal the events ,,1 and B are not independent.
(l)

I