Class 11 Mathematics Probability MCQs

Question : If a person throw 3 dice, the probability of getting sum of digit exactly 15 is :       
(a) 1/108
(b) 2/109
(c) 5/108
(d) 3/108

Answer :  C


Question : The probability that at least one of the events A and B occurs is 0.6. If A and B occur simultaneously with probability 0.2, then       
P(A) + P(B) is
(a) 0.4
(b) 0.8
(c) 1.2
(d) 1.6

Answer :  C
 

Question : There are 5 pairs of shoes in a cupboard from which 4 shoes are picked at random. The probability that there is at least one pair is       
(a) 8/21
(b) 11/21
(c) 13/21
(d) 12/31

Answer :  C


Question : Three identical dice are rolled. The probability that the same number will appear on each of them is:       
(a) 1/6
(b) 1/36
(c) 1/18
(d) 3/28

Answer :  B


Question : The probability that a card drawn from a pack of 52 cards will be a diamond or king is:       
(a) 1/52
(b) 2/13
(c) 4/13
(d) 1/13

Answer :  C
 

Question : The probability, that a leap year has 53 sundays is:       
(a) 2/7
(b) 3/7
(c) 4/7
(d) 1/7

Answer :  A


Question : Let A, B, C be three events such that P (A) = 0.3, P(B) = 0.4, P(C) = 0.8, P(A ∩ B) = 0.08, P(A ∩ C) = 0.28, P(A∩B∩C) = 0.09. If P(AÈBÈC) ³ 0.75, then       
(a) 0.23 ≤ P(B∩C) ≤ 0.48
(b) 0.45 ≤ P(B∩C) ≤ 0.75
(c) 0.48 ≤ P(B∩C) ≤ 0.75
(d) none of these.

Answer :  A
 

Question : The probability that a man who is x years old will die in a year is P. Then amongst n persons A1, A2....,An each x years old now, the probability that A1 will die in one year is:       
(a) 1/n²
(b) 1 – (1 – P)n
(c) 1/n2(1 - 1 - p)n ]
(d) 1/n [1 – (1 – P)n]

Answer :  D


Question : The most probable number of heads in 80 tosses of a biased coin, given that the probability of a head in a single toss is 3/5 , is:       
(a) 48
(b) 32
(c) 16
(d) 12

Answer :  A
 

QuestionThe probability of occurrence of an event A is 0.3 and that of occurrence of an event B is 0.4. If A and B are mutually exclusive, then the probability that neither A occurs nor B occurs is:       
(a) 0.2
(b) 0.35
(c) 0.3
(d) none of these

Answer :  C


Question : Out of 40 consecutive integers, two are chosen at random, the probability that their sum is odd is:       
(a) 14/29
(b) 21/29
(c) 22/39
(d) 20/39

Answer :  D


Question : A drawer contains 5 brown socks and 4 blue socks well mixed. A man reaches the drawer and pulls out 2 socks at random. What is the probability that they match ?       
(a) 2/9
(b) 4/9
(c) 5/9
(d) 5/8

Answer :  B

Question : Out of 600 bolts, 20% are too large and 10% are too small. The remainder are considered to be suitable. If a bolt is selected at random, the probability that it will be suitable is:     
(a) 1/5
(b) 7/10
(c) 1/10
(d) 3/10

Answer :  B
 

Question : In a collection of 6 mathematics books and 4 physics books, the probability that 3 particular mathematics books will be together is:       
(a) 1/8
(b) 1/10
(c) 1/15
(d) 1/20

Answer :  C


Question : A die is thrown. Let A be the event that the number obtained is greater than 3. Let B be the event that the number obtained is less than 5.       
Then P(AÈB) is
(a) 3/5
(b) 0
(c) 1
(d) 2/5

Answer :  C


Question : An urn contains 13 balls numbering 1 to 13 . The probability that a ball selected at random is a ball with a number that is a multiple of 3 or 4 is equal to:       
(a) 6/13
(b) 5/13
(c) 4/13
(d) 2/13

Answer :  A


Question : The number 1, 2, 3, ......., n are arranged in a random order. The probabiltiy that the digits 1, 2, 3, .....k (k < n) appears as neighbours in that order is       
(a) 1 /1n! 
(b) k!/n!
(c) (n – k)! /n!
(d) (n – k +1)! /n!

Answer :  D


Question : The probability of having a king and a queen when the two cards are drawn at random from a pack of 52 cards is:       
(a) 16/663
(b) 8/663
(c) 4/663
(d) 2/663

Answer :  B


Question : If A and B are two events, such that P(A ∪ B) 3/4 , P(A ∩ B) 1/4 ,P(A^c ) 2/3  WHere Ac stands for the complementary event of A, then P(B) is given by:
(a) 1/3
(b) 2/3
(c) 1/9
(d) 2/9

Answer :  B


Question : In tossing 10 coins the probability of getting 5 heads is:       
(a) 1 /2
(b) 63/256
(c) 193/250
(d) 9/128

Answer :  B
 

Question : Three identical dice are rolled. The probability that the same number will appear on each of them is:       
(a) 1/6
(b) 1/36
(c) 1/18
(d) 3/28

Answer :  B


Question : A dice is tossed twice. The probability of having a number greater than 3 on each toss is:       
(a) 1/4
(b) 1/3
(c) 1/2
(d) 1

Answer :  C
 

Question : In a box there are 2 red, 3 black and 4 white balls.        
Out of these three balls are drawn together. The probability of these being of same colour is:
(a) 5/84
(b) 1/21
(c) 1/84
(d) none of these

Answer :  A
 

Question : Five horses are in a race. Mr. A selects two of the horses at random and bets on them. The probability that Mr. A selected the winning horse is       
(a) 5/2
(b) 5/4
(c) 5/3
(d) 5/1

Answer :  A


Question : A box contains 10 identical electronic components of which 4 are defective. If 3 components are selected at random from the box in succession, without replacing the units already drawn, what is the probability that two of the selected components are defective?       
(a) 1/5
(b) 5/24
(c) 3/10
(d) 1/40

Answer :  C
 

Question : In a school there are 40% science students and the remaining 60% are arts students. It is known that 5% of the science students are girls and 10% of the arts students are girls. One student selected at random is a girl. What is the probability that she is an arts student?       
(a) 1/3
(b) 3/4
(c) 1/5
(d) 3/5
 

Answer :  B
 

Question : A and B play a game where each is asked to select a number from 1 to 25. If the two numbers match, both of them win a prize. The probbility that they will not win a prize in a single trial is       
(a) 1/25
(b) 24/25
(c) 2/25
(d) None

Answer :  B