Page 198 - Engineering Mathematics Workbook_Final

Probability & Statistics

1 1 325
(a) (b) (a) 0 (b)
18 4 864
2 5 525 5
(c) (d) (c) (d)
9 18 864 12
[GATE-2015 (ME-SET2)] [GATE 2018 (EE)]
209. Candidates were asked to come to an 212. A person moving through a
interview with 3 pens each. Black, tuberculosis prone zone has a 50%
Blue, green and red were the probability of becoming infected.
permitted pen colours that the However, only 30% of infected
candidate could bring. The people developed the disease. What
probability that a candidate comes percentage of people developed the
with all 3 pens having the same disease. What percentage of people
colour is ____. moving through a tuberculosis prone
[GATE-2016-EE-SET 1] zone remains infected but does not
210. P and Q are considering to apply for a show symptoms of disease?
job. The probability that P applies for (a) 15 (b) 33
1 (c) 35 (d) 37
the job is . The probability that P [GATE-2016]
4
applies for the job given that Q 213. A pair of dice is rolled again and
1 again till a total of 5 or 7 is obtained.
applies for the job is , and the The chance that a total 5 comes
2 before a total of 7 is
probability that Q applies for the job 2 3
1 (a) (b)
given that P applies for the job is . 5 7
3 3
Then the probability that P does not (c) (d) none of these
apply for the job given that Q does 13
not apply for the job is 214. A bag P contains 3 white and 4 black
4 5 balls and another bag Q contains 4
(a) (b) white and three black balls. A ball is
5 6 transferred (at random) from bag P to
7 11
(c) (d) the bag Q and then a ball is
8 12 transferred from bag Q to the bag P.
[GATE-2017 PAPER-2 (CS)] A ball is then taken out from the bag
211. A class of twelve children has two P. The chance that it is a white ball is
more boys, then girls. A group of 31 25
three children are randomly picked (a) 56 (b) 49
from this class to accompany the 25
teacher on a field trip. What is the (c) (d) none of these
probability that the group 56
accompanying the teacher contains 215. There are two identical locks with
more girls than boy? two identical keys and the key are
among six different ones which a
person carries in his pocket. In hurry
he drops one key somewhere. Then

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