Page 169 - Engineering Mathematics Workbook_Final

Probability & Statistics

hours given that it is of type 1 is 0.7, 27. Two coins are tossed simultaneously.
and given that it is of type 2 is 0.4. The probability (upto the decimal
The probability that an LED bulb points accuracy) of getting at least
chosen uniformly at random lasts one head is __________.
more than 100 hours is

____________. [GATE-2017-ME-SESSION-2]
28. The number of integers between 1
[GATE-2016-CS-SET-2] and 500 (both inclusive) that are

divisible by 3 or 5 or 7 is
24. Three fair cubical dice are thrown
simultaneously. The probability that ___________. [GATE-2017]
all three dice have the same number 29. The probability that a k-digit code
on the faces showing up is (up to does NOT contain the digits 0, 5 or 9
third decimal place) _____________. is

[GATE-2017-EC-SESSION-1] k k
(a) 0.3 (b) 0.6
25. An urn contains 5 red balls and 5 k k
black balls. In the first draw, one ball (c) 0.7 (d) 0.9
is picked at random and discarded [GATE-2017 - EE]
without noticing its colour. The
probability to get a red ball in the 30. The probability that a communication
second draw is system will have high fidelity is 0.81.

1 4 The probability that the system will
(a) (b) have both high fidelity and high
2 9
selectivity is 0.18. The probability
5 6 that a given system with high fidelity
(c) (d)
9 9 will have high selectivity is

[GATE-2017-EE-SESSION-2] (a) 0.181 (b) 0.191

26. A two-faced fair coin has its faces (c) 0.222 (d) 0.826
designated as head (H) and tail (T).
This coin is tossed three times in [GATE-2017 (IN)]
succession to record the following
outcomes: H.H.H. If the coin is 31. Two dice are thrown simultaneously.
tossed one more time, the probability The probability that the product of
(up to one decimal place) of the numbers appearing on the top
obtaining H again given the previous faces of the dice is a perfect square is
realisations of H, H and H. would be
________ (a) 1/9 (b) 2/9

[GATE-2017-CE-SESSION-2] (c) 1/3 (d) 4/9

[GATE-2017-IN]

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