800 families having 3 children only were surveyed in a backward town and following data were collected: Number of girls 0 1 2 3 Number of families 140 320 275 65 What is the probability of having all the boys in the family?

The given table is, Number of girls 0 1 2 3 Number of families 140 320 275 65 All the boys in the family means there is no girls in family. Let, E 1 = Number of families having no girls or 0 girls = 140 Total number of families = 800 P E 1 = Number of families having no girls Total number of families = 140 800 = 14 80 = 0 . 175 Hence, the probability of having all the boys in the family is 0 . 175 .

800 families having 3 children only were surveyed in a backward town and following data were collected: Number of girls 0 1 2 3 Number of families 140 320 275 65 What is the probability of having at least one girl in the family?

The given table is, Number of girls 0 1 2 3 Number of families 140 320 275 65 At least one girl in the family means, there can be one, two or three girls in the family. Let, E 1 = Number of families having one, two or three girls in the family = 320 + 275 + 65 = 660 Total number of families = 800 P E 1 = Number of families having one , two or three girls in the family Total number of families = 660 800 = 0 . 825 Hence, the probability of having at least one girl in the family is 0 . 825 .

800 families having 3 children only were surveyed in a backward town and following data were collected: Number of girls 0 1 2 3 Number of families 140 320 275 65 What is the probability of having at least one boy in the family?

The given table is, Number of girls 0 1 2 3 Number of families 140 320 275 65 At least one boy in the family means, there can be one, two or three boys in the family or there can be zero, one or two girls in the family. Let, E 1 = Number of families having zero,one or two girls in the family = 140 + 320 + 275 = 660 = 735 Total number of families = 800 P E 1 = Number of families having zero , one or two girls in the family Total number of families = 735 800 = 0 . 919 Hence, the probability of having at least one boy in the family is 0 . 919 .

The probability of guessing the correct answer to a certain question is x 2 . If probability of not guessing the correct answer is 2 3 , then find x .

Here, probability of guessing the correct answer = x 2 . And probability of not guessing the correct answer = 2 3 . Now, we know that, P (Guessing the correct answer) + P (not guessing the correct answer) = 1 Therefore, x 2 + 2 3 = 1 ⇒ 3 x + 4 6 = 1 ⇒ 3 x + 4 = 6 ⇒ 3 x = 2 ⇒ x = 2 3 Hence, the value of x is 2 3 .

A K Upadhyay and S Upadhyay Solutions for Chapter: Probability, Exercise 2: EXERCISE

Author:A K Upadhyay & S Upadhyay

A K Upadhyay Mathematics Solutions for Exercise - A K Upadhyay and S Upadhyay Solutions for Chapter: Probability, Exercise 2: EXERCISE

Attempt the practice questions on Chapter 15: Probability, Exercise 2: EXERCISE with hints and solutions to strengthen your understanding. MATHEMATICS solutions are prepared by Experienced Embibe Experts.

Questions from A K Upadhyay and S Upadhyay Solutions for Chapter: Probability, Exercise 2: EXERCISE with Hints & Solutions

HARD

9th CBSE

IMPORTANT

MATHEMATICS>Chapter 15 - Probability>EXERCISE>Q 2

A die is thrown $1000$ times with the frequencies for the outcomes $1, 2, 3, 4, 5$ and $6$ as given in the following table:

Outcome	$5 = \frac{175}{1000} = 0.175$	$2$	$3$	$4$	$5$	$6$
Frequency	$180$	$150$	$148$	$196$	$175$	$151$

EASY

9th CBSE

IMPORTANT

MATHEMATICS>Chapter 15 - Probability>EXERCISE>Q 17

$800$ families having $3$ children only were surveyed in a backward town and following data were collected:

Number of girls	$0$	$1$	$2$	$3$
Number of families	$140$	$320$	$275$	$65$

What is the probability of having all the boys in the family?

EASY

9th CBSE

IMPORTANT

MATHEMATICS>Chapter 15 - Probability>EXERCISE>Q 17

$800$ families having $3$ children only were surveyed in a backward town and following data were collected:

Number of girls	$0$	$1$	$2$	$3$
Number of families	$140$	$320$	$275$	$65$

What is the probability of having at least one girl in the family?

EASY

9th CBSE

IMPORTANT

MATHEMATICS>Chapter 15 - Probability>EXERCISE>Q 17

$800$ families having $3$ children only were surveyed in a backward town and following data were collected:

Number of girls	$0$	$1$	$2$	$3$
Number of families	$140$	$320$	$275$	$65$

What is the probability of having at least one boy in the family?

EASY

9th CBSE

IMPORTANT

MATHEMATICS>Chapter 15 - Probability>EXERCISE>Q 18

In a survey of $200$ people, it was found that $142$ read newspaper daily and rest read newspaper occasionally. Find the probability that a person chosen at random reads newspaper ocassionally correct upto two decimals.

EASY

9th CBSE

IMPORTANT

MATHEMATICS>Chapter 15 - Probability>EXERCISE>Q 18

In a survey of $200$ people, it was found that $142$ read newspaper daily and rest read newspaper occasionally. Find the probability that a person chosen at random read newspaper occasionally correct upto two decimal places.
What do you think reading newspaper daily is a good habit or just a waste of time?

MEDIUM

9th CBSE

IMPORTANT

MATHEMATICS>Chapter 15 - Probability>EXERCISE>Q 19

If the probability of success of an experiment is $0.4,$ what is the probability of failure?

EASY

9th CBSE

IMPORTANT

MATHEMATICS>Chapter 15 - Probability>EXERCISE>Q 26

The probability of guessing the correct answer to a certain question is $\frac{x}{2}$ . If probability of not guessing the correct answer is $\frac{2}{3}$ , then find $x$ .

A K Upadhyay and S Upadhyay Solutions for Chapter: Probability, Exercise 2: EXERCISE

A K Upadhyay Mathematics Solutions for Exercise - A K Upadhyay and S Upadhyay Solutions for Chapter: Probability, Exercise 2: EXERCISE

Questions from A K Upadhyay and S Upadhyay Solutions for Chapter: Probability, Exercise 2: EXERCISE with Hints & Solutions

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