Page 183 - Engineering Mathematics Workbook_Final

Probability & Statistics

−
−
3
3
(a) 2e (b) 3e 117. Let E and F be two events with P(E)
= 0.7, P(F) = 0.4 and
−
−
3
3
=
(c) 4e (d) 5e P ( E  F C ) 0.4 . Then
[MS 2011] P ( F E  / F C ) = __________
114. A four digit number is choosen at 1 1
random. The probability that there is (a) 2 (b)
3
exactly two zeroes in that number is 1 1
____________ (c) (d)
4 5

(a) 0.73 (b) 0.973 [MS 2013]

(c) 0.027 (d) 0.27 118. The probability that a hand of 5

playing cards contains at least two
[MS 2012]
aces is _________
115. A person makes repeated attempts to
4 C  48 C
destroy a target. Attempts are made (a) 2 3
independent of each other. The 52 C 5
probability of destroying the target in
any attempt is 0.8. Given that he fails (b) 4 C + 48 C 3
2
to destroy the target in first five 52 C 5
attempts, the probability that the 4 C  48 C + 48 C + 48 C 
th
target is destroyed in the 8 attempt is (c) 2   3 2 1 
52 C
(a) 0.128 (b) 0.032 5
4 C  48 C + 4 C  48 C + 4 C  48 C
(c) 0.160 (d) 0.064 (d) 2 3 3 52 C 5 2 4 1

[MS 2012]
[IISC 2003]
116. Let the random variable
)
X ~ B (5,P such that 119. Bag A contains 3 white and 4 red
balls and Bag B contains 6 white and
P ( X = ) 2 = 2P ( X = ) 3 . Then the 3 red balls. A biased coin, twice as
variance of X is ________ likely to come up heads as tail is
tossed once. If it shows head, a ball is
10 10
(a) (b) drawn from bag A. Otherwise from
3 9 bag B. Given that a white ball was

drawn, what is the probability that the
5 5
(c) (d) coin came up tail?
3 9
[JAM 2005]
[MS 2012]

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