GkSeries.com

NCERT Solutions for class 11 Maths | Chapter 16 - Probability

(1) When a coin is tossed 8 times getting a head is a success. Then the probability that at least 2 heads will occur is
[A] 247/265
[B] 73/256
[C] 247/256
[D] 27/256
Answer: 247/256
(2) The probability of getting the number 6 at least once in a regular die if it can roll it 6 times?
[A] 1 – (5/6)6
[B] 1 – (1/6)6
[C] (5/6)6
[D] (1/6)6
Answer: 1 – (5/6)6

DOWNLOAD CURRENT AFFAIRS PDF FROM APP

(3) A certain company sells tractors which fail at a rate of 1 out of 1000. If 500 tractors are purchased from this company, what is the probability of 2 of them failing within first year
[A] e-1/2/2
[B] e--1/2/4
[C] e--1/2/8
[D] none of these
Answer: e--1/2/8
(4) Three houses are available in a locality. Three persons apply for the houses. Each applies for one house without consulting others. The probability that all the three apply for the same house is
[A] 2/9
[B] 1/9
[C] 8/9
[D] 7/9
Answer: 1/9
(5) Two dice are thrown the events A, B, C are as follows A: Getting an odd number on the first die. B: Getting a total of 7 on the two dice. C: Getting a total of greater than or equal to 8 on the two dice. Then AUB is equal to
[A] 15
[B] 17
[C] 19
[D] 21
Answer: 21
(6) The probability that in a random arrangement of the letters of the word INSTITUTION the three T are together is
[A] 0.554
[B] 0.0554
[C] 0.545
[D] 0.0545
Answer: 0.0545
(7) Two unbiased dice are thrown. The probability that neither a doublet nor a total of 10 will appear is
[A] 3/5
[B] 2/7
[C] 5/7
[D] 7/9
Answer: 7/9
(8) A bag contains 5 brown and 4 white socks . A man pulls out two socks. The probability that both the socks are of the same colour is
[A] 9/20
[B] 2/9
[C] 3/20
[D] 4/9
Answer: 4/9
(9) The probability of getting 53 Sundays in a leap year is
[A] 1/7
[B] 2/7
[C] 3/7
[D] None of these
Answer: 2/7
(10) The probability that when a hand of 7 cards is drawn from a well-shuffled deck of 52 cards, it contains 3 Kings is
[A] 1/221
[B] 5/716
[C] 9/1547
[D] None of these
Answer: 9/1547
(11) A couple has two children. The probability that both children are females if it is known that the elder child is a female is
[A] 0
[B] 1
[C] 1/2
[D] 1/3
Answer: 1/2
(12) Two cards from a pack of 52 cards are lost. One card is drawn from the remaining cards. If drawn card is diamond then the probability that the lost cards were both hearts is
[A] 143/1176
[B] 143/11760
[C] 143/11706
[D] 134/11760
Answer: 143/11760
(13) There are four machines and it is known that exactly two of them are faulty. They are tested, one by one, in a random order till both the faulty machines are identified. Then the probability that only two tests are needed is
[A] 1/3
[B] 1/6
[C] 1/2
[D] 1/4
Answer: 1/6
(14) Let A and B are two mutually exclusive events and if P(A) = 0.5 and P(B ̅) = 0.6 then P(A∪B) is
[A] 0
[B] 1
[C] 0.6
[D] 0.9
Answer: 0.9
(15) 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: 1/36
(16) If four whole numbers taken at random are multiplied together, then the chance that the last digit in the product is 1, 3, 5, 7 is
[A] 16/25
[B] 16/125
[C] 16/625
[D] none of these
Answer: 16/625
(17) Two numbers are chosen from {1, 2, 3, 4, 5, 6} one after another without replacement. Find the probability that the smaller of the two is less than 4.
[A] 4/5
[B] 1/15
[C] 1/5
[D] 14/15
Answer: 4/5
(18) A certain company sells tractors which fail at a rate of 1 out of 1000. If 500 tractors are purchased from this company, what is the probability of 2 of them failing within first year
[A] e-1/2/2
[B] e-1/2/4
[C] e-1/2/8
[D] none of these
Answer: e-1/2/8
(19) A random variable X has poison distribution with mean 2. Then, P (X > 1.5) equals
[A] 1 – 3/e²
[B] 2/e²
[C] 3/e²
[D] 0
Answer: 1 – 3/e²
(20) On his vacation, Rahul visits four cities (A, B, C, and D) in a random order. The probability that he visits A first and B last is
[A] 1/2
[B] 1/6
[C] 1/10
[D] 1/12
Answer: 1/12

Please share this page

Chapters

Click Here to Read more questions

Teacher Eligibility Test