Page 91 - DMTH404_STATISTICS

Unit 6: Probability

Equally likely outcomes: The outcomes of random experiment are said to be equally likely or Notes
equally probable if the occurrence of none of them is expected in preference to others. For
example, if an unbiased coin is tossed, the two possible outcomes, a head or a tail are equally
likely.

6.9 Self Assessment

Choose the appropriate answer:

(
1. If A and B are any two events of a sample space S, then ( P A ) B +P A  ) B equals
(a) P ( ) +A P ( ) B
1- P A  d Bi
(b)
1- P A  d Bi
(c)
(d) none of the above.
2. If A and B are independent and mutually exclusive events, then
P A a f = P A/Bf
a
(a)
P B a f = P B/Af
a
(b)
(c) either P(A) or P(B) or both must be zero.
(d) none of the above.
If A and B are independent events, then P A b
3. Bg equals
P A a f+P B a f
(a)
a
P A a f.P B/Af
(b)
P B a f.P A/Bf
a
(c)
P A a f.P B a f
(d)
If A and B are independent events, then P A B b
4. g equals
P A a f.P B a f+P B a f
(a)
P A a f.P B d i+P B a f
(b)
P A d i.P B d i+P A a f
(c)
(d) none of the above.
1
5. If A and B are two events such that P A b Bg = 5 , P A b Bg = 1 , P A d i = , the events are
6 3 3
(a) dependent
(b) independent
(c) mutually exclusive
(d) none of the above.
6. Four dice and six coins are tossed simultaneously. The number of elements in the sample
space are
6
4
6
2
6
2
(a) 4  6 (b) 2  6 (c) 6  2 (d) none of these.
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