<\/span><\/h2>\nQuestion 1.
The probability of an impossible event is
(a) 1
(b) 0
(c) less than 0
(d) greater than 1
Solution:
The probability of an impossible event is 0 (b)<\/p>\n
Question 2.
The probability on a certain event is
(a) 0
(b) 1
(c) greater than 1
(d) less than 1
Solution:
The probability of a certain event is 1 (b)<\/p>\n
Question 3.
The probability of an event of a trial is
(a) 1
(b) 0
(c) less than 1
(d) more than 1
Solution:
The probability of an even of a trial is less than 1 (c)<\/p>\n
Question 4.
Which of the following cannot be the probability of an event?
(a)\u00a01<\/span>3<\/span><\/span><\/span><\/span><\/span>
(b)\u00a03<\/span>5<\/span><\/span><\/span><\/span><\/span>
(c)\u00a05<\/span>3<\/span><\/span><\/span><\/span><\/span>
(d) 1
Solution:
The probability of an event is less than 1
5<\/span>3<\/span><\/span><\/span><\/span><\/span>\u00a0i.e .1<\/span>2<\/span>3<\/span><\/span><\/span><\/span><\/span>\u00a0is not the probability<\/p>\nQuestion 5.
Two coins are tossed simultaneously. The probability of getting atmost one head is
(a)\u00a01<\/span>4<\/span><\/span><\/span><\/span><\/span>
(b)\u00a03<\/span>4<\/span><\/span><\/span><\/span><\/span>
(c)\u00a01<\/span>2<\/span><\/span><\/span><\/span><\/span>
(d)\u00a01<\/span>4<\/span><\/span><\/span><\/span><\/span>
Solution:
Total number of possible events (n) = 2 + 2 = 4
Number of events coming at the most 1 head (m) 2 times + 1 times = 3
Probability P(A) =\u00a0m<\/span>n<\/span><\/span><\/span><\/span><\/span>\u00a0=\u00a03<\/span>4<\/span><\/span><\/span><\/span><\/span>\u00a0(b)<\/p>\nQuestion 6.
A coin is tossed 1000 times, if the probability of getting a tail is 3\/8, how many times head is obtained?
(a) 525
(b) 375
(c) 625
(d) 725
Solution:
No. of times a coin is tossed (n) = 1000
Probability of getting a tail =\u00a03<\/span>8<\/span><\/span><\/span><\/span><\/span>
Let No. of tail come = x
Probability P(A) =\u00a0m<\/span>n<\/span><\/span>=<\/span>x<\/span>1000<\/span><\/span><\/span><\/span><\/span>
x<\/span>1000<\/span><\/span><\/span><\/span><\/span>\u00a0=\u00a03<\/span>8<\/span><\/span><\/span><\/span><\/span>
=>\u00a0x<\/span>1000<\/span><\/span>=<\/span>3<\/span>8<\/span><\/span><\/span><\/span><\/span>\u00a0=>\u00a03<\/span>X<\/span>1000<\/span><\/span>8<\/span><\/span>=<\/span>3<\/span>X<\/span>125<\/span><\/span><\/span><\/span>
=> x = 375
\u2234 No. of heads are obtained = 1000 \u2013 375 = 625 (c)<\/p>\nQuestion 7.
A dice is rolled 600 times and the occurrence of the outcomes 1, 2, 3, 4, 5 and 6 are given below:<\/p>\n
![\"\"](\"https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/09\/chapter-25-4.png\")
<\/p>\n
The probability of getting a prime number is
(a)1<\/span>3<\/span><\/span><\/span><\/span><\/span>
(b)2<\/span>3<\/span><\/span><\/span><\/span><\/span>
(c)49<\/span>60<\/span><\/span><\/span><\/span><\/span>
(d)39<\/span>125<\/span><\/span><\/span><\/span><\/span>
Solution:
Total number of times a dice is rolled (n) = 600<\/p>\n![\"\"](\"https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/09\/chapter-25-5.png\")
<\/p>\n
Now total number of times getting a prime number i.e. 2, 3, 5, (m) = 30 + 120 + 50 = 200
Probability P(A) =\u00a0m<\/span>n<\/span><\/span><\/span><\/span><\/span>\u00a0=\u00a0200<\/span>600<\/span><\/span><\/span><\/span><\/span>\u00a0=\u00a01<\/span>3<\/span><\/span><\/span><\/span><\/span>\u00a0(a)<\/p>\nQuestion 8.
The percentage of attendance of different classes in a year in a school is given below:<\/p>\n
![\"\"](\"https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/09\/chapter-25-6.png\")
<\/p>\n
What is the probability that the class attendance is more than 75%?
(a)\u00a01<\/span>6<\/span><\/span><\/span><\/span><\/span>
(b)\u00a01<\/span>3<\/span><\/span><\/span><\/span><\/span>
(c)\u00a05<\/span>6<\/span><\/span><\/span><\/span><\/span>
(d)\u00a01<\/span>2<\/span><\/span><\/span><\/span><\/span>
Solution:
Percentage of attendance of different classes<\/p>\n![\"\"](\"https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/09\/chapter-25-97.png\")
<\/p>\n
Total attendance more than 75% (m) VIII,VII and VI = 3 classes
and total number of classes (n) = 6
Probability P(A) =\u00a03<\/span>6<\/span><\/span><\/span><\/span><\/span>\u00a0=\u00a01<\/span>2<\/span><\/span><\/span><\/span><\/span>.<\/p>\nQuestion 9.
A bag contains 50 coins and each coin is marked from 51 to 100. One coin is picked at random.
The probability that the number on the coin is not a prime number, is
(a)\u00a01<\/span>5<\/span><\/span><\/span><\/span><\/span>
(b)\u00a03<\/span>5<\/span><\/span><\/span><\/span><\/span>
(c)\u00a0
![\"RD](\"https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/09\/RD-Sharma-Class-9-Solutions-Chapter-25-MCQS.jpg\")
<\/p>\n