Page 170 - Engineering Mathematics Workbook_Final

Probability & Statistics

32. A box has 6 red balls and 4 while 35. A bag contains 7 red and 4 white
balls. A ball is picked at random and balls. Two balls are drawn at random.
replaced in the box, after which a What is the probability that both the
second balls is picked. balls are red?
28 21
The probability of both the balls (a) 55 (b) 55
being red, rounded to 2 decimal
places, is ________. 7 4
(c) (d)
[GATE-2017-CH] 55 55
[ESE – 2017 - EE]
33. P and Q are considering to apply for a
job. The probability that P applies for 36. Probability (up to one decimal place)
of consecutively picking 3 red balls
1
the job is . The probability that P without replacement from a box
4 containing 5 red balls and 1 white

applies for the job given that Q ball is _________.
1
applies for the job is , and the [GATE-2018-CE-AFTERNOON
2 SESSION]

probability that Q applies for the job 37. An unbiased coin is tossed six times
1 in a row and four different such trials
given that P applies for the job is .
3 are conducted.
Then the probability that P does not One train implies six tosses of the
apply for the job given that Q does coin. If H stands for head and T

not apply for the job is stands for tail, the following are the
observations from the four trials.
4 5
(a) (b) (1) HTHTHT (2) TTRHHHT
5 6
(3) HTTHHT (4) HHHT___
7 11
(c) (d)
8 12 Which statement describing the last
two coin tosses of the fourth trial has
[GATE-2017-PAPER-2-CS] the highest probability of being
correct?
34. There are 3 red socks, 4 green socks
and 3 blue socks, you choose 2 socks. (a) Two T will occur
The probability that they are of the (b) One H and one T will occur
same colour is ________.
(c) Two H will occur
(a) 1/5 (b) 7/30 (d) One H will be followed by one T.

(c) 1/4 (d) 4/15 [GATE-2019-ME-AFTERNOON

SESSION]
[GATE-2017-PAPER-2-CS]

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