Get here NCERT Solutions Class 12 Maths Chapter 13. These NCERT Solutions for Class 12 of Maths subject includes detailed answers of all the questions in Chapter 13 – Probability provided in NCERT Book which is prescribed for class 12 in schools.
Book: National Council of Educational Research and Training (NCERT)
Class: 12th Class
Subject: Maths
Chapter: Chapter 13 – Probability
NCERT Solutions Class 12 Maths Chapter 13 – Free Download PDF
NCERT Solutions Class 12 Maths Chapter 13 – Probability
uestion 1.
A die is thrown 6 times. If ‘getting an odd number’ is a success, what is the probability of
(i) 5 successes?
(ii) at least 5 successes?
(iii) at most 5 successes?
Solution:
Question 2.
There are 5% defective items in a large bulk of items. What is the probability that a sample of 10 items will include not more than one defective item ?
Solution:
Question 3.
A pair of dice is thrown 4 times. If getting a doublet is considered a success, find the probability, of two successes.
Solution:
Question 4.
Five cards are drawn successively with replacement from a well- shuffled deck of 52 cards. What is the probability that
(i) all the five cards are spades?
(ii) only 3 cards are spades?
(iii) none is spade?
Solution:
Question 5.
The probability that a bulb produced by a factory will fuse after 150 days of use is 0.05. Find the probability that out of 5 such bulbs.
(i) none
(ii) not more than one
(iii) more than one
(iv) at least one will fuse after 150 days of use
Solution:
Question 6.
A bag consists of 10 balls each marked with one of the digits 0 to 9. If four bails are drawn successively with replacement from the bag, what is the probability that none is marked with the digit 0?
Solution:
Question 7.
In an examination, 20 questions of true – false type are asked. Suppose a student tosses fair coin to determine his answer to each question. If the coin falls heads, he answers ‘true,’ if it falls tails, he answers “ false’. Find the probability that he answers at least 12 questions correctly.
Solution:
Question 8
Suppose X has a binomial distribution
(Hint: P (X = 3) is the maximum among all P (Xi), xi. = 0,1,2,3,4,5,6)
Solution:
Question 9.
On a multiple choice examination with three possible answers for each of the five questions, what is the probability that a candidate would get four or more correct answers just by guessing?
Solution:
Question 10.
A person buys a lottery ticket in 50 lotteries, in each of which his chance of winning a prize is
(a) at least once,
(b) exactly once,
(c) at least twice?
Solution:
Question 11.
Find the probability of getting 5 exactly twice in 7 throws of a die.
Solution:
Question 12.
Find the probability of throwing at most 2 sixes in 6 throws of a single die.
Solution:
Question 13.
It is known that 10% of certain articles manufactured are defective. What is the probability that in a random sample of 12 such articles 9 are defective?
Solution:
Question 14.
In a box containing 100 bulbs, 10 are defective. The probability that out of a sample of 5 bulbs, none is defective is
(a)
(b)
(c)
(d)
Solution:
Question 15.
The probability that a student is not a swimmer is
Solution:
