BITSAT SERIES Mathematics
Probability
44 previous year questions.
Volume: 44 Ques
Yield: High
High-Yield Trend
6
2025 4
2024 4
2023 3
2021 2
2020 3
2019 2
2018 3
2017 2
2016 3
2015 2
2014 1
2013 2
2012 3
2011 2
2010 Chapter Questions 44 MCQs
01
PYQ 2005
medium
mathematics ID: bitsat-2
Let be a set containing n elements and we select two subsets and of S at random, then the probability that and is:
1
2
3
4
02
PYQ 2009
medium
mathematics ID: bitsat-2
The random variable X has the following probability distribution |c|c|c|c|c|c| x & 0 & 1 & 2 & 3 & 4
P(X=x) & k & 3k & 5k & 2k & k
Then the value of P(X\ge2) is
P(X=x) & k & 3k & 5k & 2k & k
Then the value of P(X\ge2) is
1
\frac13
2
\frac23
3
\frac34
4
\frac14
03
PYQ 2010
medium
mathematics ID: bitsat-2
If mean of a Poisson distribution of a random variable X is 2, then the value of P(X>1.5) is
1
3e²
2
3e
3
1-3e
4
1-3e²
04
PYQ 2010
medium
mathematics ID: bitsat-2
A black die and a white die are rolled. Find the probability that the number shown by the black die will be more than twice that shown by the white die.
1
(1)/(8)
2
(1)/(6)
3
(1)/(3)
4
(1)/(4)
05
PYQ 2011
medium
mathematics ID: bitsat-2
If A and B are mutually exclusive events and if P(B)=13, P(A B)=(13)/(21), then P(A) is equal to:
1
17/21
2
4/7
3
2/7
4
5/7
06
PYQ 2011
medium
mathematics ID: bitsat-2
A die is loaded such that the probability of throwing the number is proportional to its reciprocal. The probability that 3 appears in a single throw is:
1
3/22
2
3/11
3
9/22
4
None of these
07
PYQ 2011
medium
mathematics ID: bitsat-2
A bag contains white and black balls. One ball is drawn at random. Then the probability that it is white is:
1
2
3
4
08
PYQ 2012
medium
mathematics ID: bitsat-2
Two dice are thrown together 4 times. The probability that both dice will show same numbers twice is:
1
2
3
4
None of these
09
PYQ 2012
medium
mathematics ID: bitsat-2
The probability of simultaneous occurrence of at least one of two events A and B is . If the probability that exactly one of A, B occurs is , then is equal to:
1
2
3
4
10
PYQ 2013
medium
mathematics ID: bitsat-2
The probability of India winning a test match against West Indies is . Assuming independence from match to match, the probability that in a 5 match series India’s second win occurs at the third test is
1
2
3
4
11
PYQ 2014
medium
mathematics ID: bitsat-2
A bag contains coins. It is known that one of these coins shows heads on both sides, whereas the other coins are fair. One coin is selected at random and tossed. If the probability that toss results in heads is , then the value of is
1
2
3
4
None of these
12
PYQ 2014
medium
mathematics ID: bitsat-2
A bag contains 5 brown and 4 white socks. A man pulls out 2 socks. Find the probability that they are of the same colour.
1
2
3
4
13
PYQ 2015
medium
mathematics ID: bitsat-2
A bag contains red and white balls. Two balls are drawn one by one. The probability that they are of different colours is.
1
2
3
4
None of these
14
PYQ 2015
medium
mathematics ID: bitsat-2
A bag contains 3 red and 3 white balls. Two balls are drawn one by one. The probability that they are of different colours is
1
2
3
4
None of these
15
PYQ 2015
medium
mathematics ID: bitsat-2
A bag contains coins. It is known that of these coins have a head on both sides, whereas the remaining coins are fair. A coin is picked up at random from the bag and tossed. If the probability that the toss results in a head is , then is equal to
1
2
3
4
16
PYQ 2016
medium
mathematics ID: bitsat-2
If three vertices of a regular hexagon are chosen at random, then the chance that they form an equilateral triangle is
1
2
3
4
\dfrac12
17
PYQ 2016
medium
mathematics ID: bitsat-2
A man takes a step forward with probability 0.4 and backward with probability 0.6. The probability that at the end of ten steps he is one step away from the starting point is
1
2
3
4
none of these
18
PYQ 2017
medium
mathematics ID: bitsat-2
A random variable has the probability distribution given. For the events and , then is
1
0.50
2
0.77
3
0.35
4
0.87
19
PYQ 2017
medium
mathematics ID: bitsat-2
One mapping is selected at random from all mappings of the set
S=1,2,3,… ,n
into itself. The probability that it is one–one is (3)/(32). Then the value of n is
1
3
2
4
3
5
4
6
20
PYQ 2017
medium
mathematics ID: bitsat-2
An urn contains five balls. Two balls are drawn and found to be white. The probability that all the balls are white is
1
2
3
4
(1)/(2)
21
PYQ 2018
medium
mathematics ID: bitsat-2
The probability of getting in a single throw of three fair dice is :
1
2
3
4
22
PYQ 2018
medium
mathematics ID: bitsat-2
The probability of getting 10 in a single throw of three fair dice is:
1
2
3
4
(1)/(5)
23
PYQ 2019
medium
mathematics ID: bitsat-2
A bag contains coins out of which are unfair with heads on both sides and the remaining are fair. One coin is picked from the bag at random and tossed. If the probability that head falls in the toss is , then the number of unfair coins in the bag is
1
18
2
15
3
13
4
14
24
PYQ 2019
medium
mathematics ID: bitsat-2
A bag contains 3 red and 3 white balls. Two balls are drawn one by one. The probability that they are of different colours is
1
2
3
4
None of these
25
PYQ 2019
medium
mathematics ID: bitsat-2
A bag contains (2n+1) coins. It is known that n of these coins have a head on both sides, whereas the remaining (n+1) coins are fair. A coin is picked up at random from the bag and tossed. If the probability that the toss results in a head is (31)/(42), then n is equal to
1
2
3
4
13
26
PYQ 2020
medium
mathematics ID: bitsat-2
If three vertices of a regular hexagon are chosen at random, then the chance that they form an equilateral triangle is
1
2
3
4
(1)/(2)
27
PYQ 2020
easy
mathematics ID: bitsat-2
A man takes a step forward with probability 0.4 and backward with probability 0.6. The probability that at the end of eleven steps he is one step away from the starting point is
28
PYQ 2021
medium
mathematics ID: bitsat-2
An urn contains five balls. Two balls are drawn and found to be white. The probability that all the balls are white is
1
(1)/(10)
2
(3)/(10)
3
(3)/(5)
4
(1)/(2)
29
PYQ 2021
medium
mathematics ID: bitsat-2
One mapping is selected at random from all mappings of the set S=1,2,3,…,n into itself.
The probability that it is one–one is (3)/(32). Then the value of n is
1
3
2
4
3
5
4
6
30
PYQ 2021
medium
mathematics ID: bitsat-2
A random variable X has the probability distribution
X: 1, 2, 3, 4, 5, 6, 7, 8
P(X): 0.15, 0.23, 0.12, 0.10, 0.20, 0.08, 0.07, 0.05
P(X): 0.15, 0.23, 0.12, 0.10, 0.20, 0.08, 0.07, 0.05
For the events E = X is a prime and F = X < 4, find P(E ∪ F).
1
0.50
2
0.77
3
0.35
4
0.87
31
PYQ 2023
easy
mathematics ID: bitsat-2
A pack of cards contains 4 aces, 4 kings,4 queens, 4 jacks. Two cards are drawn from the deck, find out the probability that at least one of them is ace.
32
PYQ 2023
easy
mathematics ID: bitsat-2
What is the probability of 53 Fridays in an ordinary year?
33
PYQ 2023
medium
mathematics ID: bitsat-2
The probability that a card drawn from a pack of 52 cards will be a diamond or a king is:
1
2
3
4
34
PYQ 2023
medium
mathematics ID: bitsat-2
The probability of getting a sum greater than 7 when a pair of dice are thrown is:
1
2
3
4
35
PYQ 2024
medium
mathematics ID: bitsat-2
A book contains 1000 pages. A page is chosen at random. The probability that the sum of the digits of the marked number on the page is equal to 9, is
1
2
3
4
None of these
36
PYQ 2024
hard
mathematics ID: bitsat-2
Given below is the distribution of a random variable :
If and , then
If and , then
1
2
3
4
37
PYQ 2024
medium
mathematics ID: bitsat-2
The probability that certain electronic component fails when first used is 0.10. If it does not fail immediately, the probability that it lasts for one year is 0.99. The probability that a new component will last for one year is
1
0.9
2
0.01
3
0.119
4
0.891
38
PYQ 2024
medium
mathematics ID: bitsat-2
The probability of getting 10 in a single throw of three fair dice is:
1
2
3
4
39
PYQ 2025
easy
mathematics ID: bitsat-2
Two dice are rolled simultaneously. What is the probability that the sum of the numbers on the two dice is at least 10?
1
2
3
4
40
PYQ 2025
hard
mathematics ID: bitsat-2
A bag contains 5 red, 3 blue, and 2 green balls. If two balls are drawn at random without replacement, what is the probability that both are red?
1
2
3
4
41
PYQ 2025
hard
mathematics ID: bitsat-2
A box contains 5 red balls and 4 green balls. Two balls are drawn one after another without replacement. What is the probability that the second ball is green, given that the first ball drawn was red?
1
2
3
4
42
PYQ 2025
medium
mathematics ID: bitsat-2
Two numbers are selected at random (without replacement) from the first 6 natural numbers. What is the probability that the difference of the numbers is less than 3?
1
2
3
4
43
PYQ 2025
medium
mathematics ID: bitsat-2
A box contains 5 red balls and 3 blue balls. If two balls are drawn randomly without replacement, what is the probability that one of the balls is red and the other is blue?
1
2
3
4
44
PYQ 2025
easy
mathematics ID: bitsat-2
From a group of 10 men and 8 women, a committee of 5 is to be formed such that it contains at least 3 women. How many such committees are possible?
1
3276
2
3500
3
3657
4
4012